diff --git a/runtime/observatory/tests/service/dominator_tree_vm_with_double_field_test.dart b/runtime/observatory/tests/service/dominator_tree_vm_with_double_field_test.dart
deleted file mode 100644
index 9edaf233a8844..0000000000000
--- a/runtime/observatory/tests/service/dominator_tree_vm_with_double_field_test.dart
+++ /dev/null
@@ -1,151 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=
-// VMOptions=--use_compactor
-// VMOptions=--use_compactor --force_evacuation
-
-import 'dart:typed_data';
-
-import 'package:observatory/service_io.dart';
-import 'package:unittest/unittest.dart';
-import 'test_helper.dart';
-
-double getDoubleWithHeapObjectTag() {
-  final bd = ByteData(8);
-  bd.setUint64(0, 0x8000000000000001, Endian.host);
-  final double v = bd.getFloat64(0, Endian.host);
-  return v;
-}
-
-// small example from [Lenguaer & Tarjan 1979]
-class R {
-  final double fld = getDoubleWithHeapObjectTag();
-  var x;
-  var y;
-  var z;
-}
-
-class A {
-  var x;
-}
-
-class B {
-  var x;
-  var y;
-  var z;
-}
-
-class C {
-  var x;
-  var y;
-}
-
-class D {
-  var x;
-}
-
-class E {
-  var x;
-}
-
-class F {
-  var x;
-}
-
-class G {
-  var x;
-  var y;
-}
-
-class H {
-  var x;
-  var y;
-}
-
-class I {
-  var x;
-}
-
-class J {
-  var x;
-}
-
-class K {
-  var x;
-  var y;
-}
-
-class L {
-  var x;
-}
-
-var r;
-
-buildGraph() {
-  r = new R();
-  var a = new A();
-  var b = new B();
-  var c = new C();
-  var d = new D();
-  var e = new E();
-  var f = new F();
-  var g = new G();
-  var h = new H();
-  var i = new I();
-  var j = new J();
-  var k = new K();
-  var l = new L();
-
-  r.x = a;
-  r.y = b;
-  r.z = c;
-  a.x = d;
-  b.x = a;
-  b.y = d;
-  b.z = e;
-  c.x = f;
-  c.y = g;
-  d.x = l;
-  e.x = h;
-  f.x = i;
-  g.x = i;
-  g.y = j;
-  h.x = e;
-  h.y = k;
-  i.x = k;
-  j.x = i;
-  k.x = i;
-  k.y = r;
-  l.x = h;
-
-  expect(r.fld, getDoubleWithHeapObjectTag());
-}
-
-var tests = <IsolateTest>[
-  (Isolate isolate) async {
-    final graph = await isolate.fetchHeapSnapshot().done;
-
-    node(String className) {
-      return graph.objects.singleWhere((v) => v.klass.name == className);
-    }
-
-    expect(node('I').parent, equals(node('R')));
-    expect(node('K').parent, equals(node('R')));
-    expect(node('C').parent, equals(node('R')));
-    expect(node('H').parent, equals(node('R')));
-    expect(node('E').parent, equals(node('R')));
-    expect(node('A').parent, equals(node('R')));
-    expect(node('D').parent, equals(node('R')));
-    expect(node('B').parent, equals(node('R')));
-
-    expect(node('F').parent, equals(node('C')));
-    expect(node('G').parent, equals(node('C')));
-    expect(node('J').parent, equals(node('G')));
-    expect(node('L').parent, equals(node('D')));
-
-    expect(node('R'), isNotNull); // The field.
-  },
-];
-
-main(args) => runIsolateTests(args, tests, testeeBefore: buildGraph);
diff --git a/runtime/platform/globals.h b/runtime/platform/globals.h
index 26c981db91325..3e16778f3ba52 100644
--- a/runtime/platform/globals.h
+++ b/runtime/platform/globals.h
@@ -417,10 +417,6 @@ typedef simd128_value_t fpu_register_t;
 #define DUAL_MAPPING_SUPPORTED 1
 #endif
 
-#if defined(DART_PRECOMPILED_RUNTIME) || defined(DART_PRECOMPILER)
-#define SUPPORT_UNBOXED_INSTANCE_FIELDS
-#endif
-
 // Short form printf format specifiers
 #define Pd PRIdPTR
 #define Pu PRIuPTR
diff --git a/runtime/platform/utils.h b/runtime/platform/utils.h
index 38d4d2f1bb1fd..ee24ad6d28d3c 100644
--- a/runtime/platform/utils.h
+++ b/runtime/platform/utils.h
@@ -21,7 +21,7 @@ class Utils {
   }
 
   template <typename T>
-  static constexpr inline T Maximum(T x, T y) {
+  static inline T Maximum(T x, T y) {
     return x > y ? x : y;
   }
 
@@ -352,18 +352,12 @@ class Utils {
     return bit_cast<word>(mask);
   }
 
-  template <typename T = uword>
-  static T Bit(uint32_t n) {
-    ASSERT(n < sizeof(T) * kBitsPerByte);
-    T bit = 1;
+  static uword Bit(uint32_t n) {
+    ASSERT(n < kBitsPerWord);
+    uword bit = 1;
     return bit << n;
   }
 
-  template <typename T>
-  DART_FORCE_INLINE static bool TestBit(T mask, intptr_t position) {
-    return ((mask >> position) & 1) != 0;
-  }
-
   // Decode integer in SLEB128 format from |data| and update |byte_index|.
   template <typename ValueType>
   static ValueType DecodeSLEB128(const uint8_t* data,
diff --git a/runtime/tests/vm/dart/unboxed_fields_type_args_test.dart b/runtime/tests/vm/dart/unboxed_fields_type_args_test.dart
deleted file mode 100644
index d19c5e9372ca3..0000000000000
--- a/runtime/tests/vm/dart/unboxed_fields_type_args_test.dart
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'dart:typed_data';
-import 'dart:async';
-import 'dart:isolate';
-
-import "package:expect/expect.dart";
-
-double getDoubleWithHeapObjectTag() {
-  final bd = ByteData(8);
-  bd.setUint64(0, 0x8000000000000001, Endian.host);
-  final double v = bd.getFloat64(0, Endian.host);
-  return v;
-}
-
-class Foo {
-  final String clazz = "foo";
-  final double x = getDoubleWithHeapObjectTag();
-}
-
-// Here we ensure to have a GC pointer and a non-GC pointer field, and then a
-// type argument vector, so the offset in number of words for the type arguments
-// will be different between host and target when compiling from 64-bit to
-// 32-bit architectures.
-class Bar<T> extends Foo {
-  final String clazz = "bar";
-  final double y = getDoubleWithHeapObjectTag();
-  final T value;
-  Bar(T val) : value = val;
-}
-
-main() async {
-  final receivePort = new ReceivePort();
-  receivePort.sendPort.send(Foo());
-  receivePort.sendPort.send(Bar<String>("StringBar"));
-  receivePort.sendPort.send(Bar<double>(4.2));
-  final it = StreamIterator(receivePort);
-
-  Expect.isTrue(await it.moveNext());
-  final foo = it.current as Foo;
-
-  Expect.isTrue(await it.moveNext());
-  final string_bar = it.current as Bar<String>;
-
-  Expect.isTrue(await it.moveNext());
-  final double_bar = it.current as Bar<double>;
-
-  Expect.equals(string_bar.value, "StringBar");
-  Expect.equals(string_bar.clazz, "bar");
-  Expect.equals(string_bar.y, getDoubleWithHeapObjectTag());
-  Expect.equals(string_bar.x, getDoubleWithHeapObjectTag());
-  Expect.equals(double_bar.value, 4.2);
-  Expect.equals(foo.clazz, "foo");
-  Expect.equals(foo.x, getDoubleWithHeapObjectTag());
-
-  await it.cancel();
-}
diff --git a/runtime/vm/bootstrap.cc b/runtime/vm/bootstrap.cc
index ff1c7b7eeb56e..584baa39136f9 100644
--- a/runtime/vm/bootstrap.cc
+++ b/runtime/vm/bootstrap.cc
@@ -71,17 +71,17 @@ static void Finish(Thread* thread) {
   // Verify that closure field offsets are identical in Dart and C++.
   ASSERT(fields.Length() == 6);
   field ^= fields.At(0);
-  ASSERT(field.HostOffset() == Closure::instantiator_type_arguments_offset());
+  ASSERT(field.Offset() == Closure::instantiator_type_arguments_offset());
   field ^= fields.At(1);
-  ASSERT(field.HostOffset() == Closure::function_type_arguments_offset());
+  ASSERT(field.Offset() == Closure::function_type_arguments_offset());
   field ^= fields.At(2);
-  ASSERT(field.HostOffset() == Closure::delayed_type_arguments_offset());
+  ASSERT(field.Offset() == Closure::delayed_type_arguments_offset());
   field ^= fields.At(3);
-  ASSERT(field.HostOffset() == Closure::function_offset());
+  ASSERT(field.Offset() == Closure::function_offset());
   field ^= fields.At(4);
-  ASSERT(field.HostOffset() == Closure::context_offset());
+  ASSERT(field.Offset() == Closure::context_offset());
   field ^= fields.At(5);
-  ASSERT(field.HostOffset() == Closure::hash_offset());
+  ASSERT(field.Offset() == Closure::hash_offset());
 #endif  // defined(DEBUG)
 
   // Eagerly compile Bool class, bool constants are used from within compiler.
diff --git a/runtime/vm/class_finalizer.cc b/runtime/vm/class_finalizer.cc
index 5f72da186209e..a7b520f5db022 100644
--- a/runtime/vm/class_finalizer.cc
+++ b/runtime/vm/class_finalizer.cc
@@ -240,33 +240,33 @@ void ClassFinalizer::VerifyBootstrapClasses() {
 #if defined(DEBUG)
   // Basic checking.
   cls = object_store->object_class();
-  ASSERT(Instance::InstanceSize() == cls.host_instance_size());
+  ASSERT(Instance::InstanceSize() == cls.instance_size());
   cls = object_store->integer_implementation_class();
-  ASSERT(Integer::InstanceSize() == cls.host_instance_size());
+  ASSERT(Integer::InstanceSize() == cls.instance_size());
   cls = object_store->smi_class();
-  ASSERT(Smi::InstanceSize() == cls.host_instance_size());
+  ASSERT(Smi::InstanceSize() == cls.instance_size());
   cls = object_store->mint_class();
-  ASSERT(Mint::InstanceSize() == cls.host_instance_size());
+  ASSERT(Mint::InstanceSize() == cls.instance_size());
   cls = object_store->one_byte_string_class();
-  ASSERT(OneByteString::InstanceSize() == cls.host_instance_size());
+  ASSERT(OneByteString::InstanceSize() == cls.instance_size());
   cls = object_store->two_byte_string_class();
-  ASSERT(TwoByteString::InstanceSize() == cls.host_instance_size());
+  ASSERT(TwoByteString::InstanceSize() == cls.instance_size());
   cls = object_store->external_one_byte_string_class();
-  ASSERT(ExternalOneByteString::InstanceSize() == cls.host_instance_size());
+  ASSERT(ExternalOneByteString::InstanceSize() == cls.instance_size());
   cls = object_store->external_two_byte_string_class();
-  ASSERT(ExternalTwoByteString::InstanceSize() == cls.host_instance_size());
+  ASSERT(ExternalTwoByteString::InstanceSize() == cls.instance_size());
   cls = object_store->double_class();
-  ASSERT(Double::InstanceSize() == cls.host_instance_size());
+  ASSERT(Double::InstanceSize() == cls.instance_size());
   cls = object_store->bool_class();
-  ASSERT(Bool::InstanceSize() == cls.host_instance_size());
+  ASSERT(Bool::InstanceSize() == cls.instance_size());
   cls = object_store->array_class();
-  ASSERT(Array::InstanceSize() == cls.host_instance_size());
+  ASSERT(Array::InstanceSize() == cls.instance_size());
   cls = object_store->immutable_array_class();
-  ASSERT(ImmutableArray::InstanceSize() == cls.host_instance_size());
+  ASSERT(ImmutableArray::InstanceSize() == cls.instance_size());
   cls = object_store->weak_property_class();
-  ASSERT(WeakProperty::InstanceSize() == cls.host_instance_size());
+  ASSERT(WeakProperty::InstanceSize() == cls.instance_size());
   cls = object_store->linked_hash_map_class();
-  ASSERT(LinkedHashMap::InstanceSize() == cls.host_instance_size());
+  ASSERT(LinkedHashMap::InstanceSize() == cls.instance_size());
 #endif  // defined(DEBUG)
 
   // Remember the currently pending classes.
@@ -1358,7 +1358,7 @@ void ClassFinalizer::VerifyImplicitFieldOffsets() {
   fields_array ^= cls.fields();
   ASSERT(fields_array.Length() == ByteBuffer::NumberOfFields());
   field ^= fields_array.At(0);
-  ASSERT(field.HostOffset() == ByteBuffer::data_offset());
+  ASSERT(field.Offset() == ByteBuffer::data_offset());
   name ^= field.name();
   expected_name ^= String::New("_data");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
diff --git a/runtime/vm/class_table.cc b/runtime/vm/class_table.cc
index e645df31d8b77..5722c74645757 100644
--- a/runtime/vm/class_table.cc
+++ b/runtime/vm/class_table.cc
@@ -4,8 +4,6 @@
 
 #include "vm/class_table.h"
 
-#include <memory>
-
 #include "platform/atomic.h"
 #include "vm/flags.h"
 #include "vm/growable_array.h"
@@ -23,9 +21,7 @@ SharedClassTable::SharedClassTable()
     : top_(kNumPredefinedCids),
       capacity_(0),
       table_(NULL),
-      old_tables_(new MallocGrowableArray<intptr_t*>()),
-      unboxed_fields_map_(nullptr),
-      old_unboxed_fields_maps_(new MallocGrowableArray<UnboxedFieldBitmap*>()) {
+      old_tables_(new MallocGrowableArray<intptr_t*>()) {
   if (Dart::vm_isolate() == NULL) {
     ASSERT(kInitialCapacity >= kNumPredefinedCids);
     capacity_ = kInitialCapacity;
@@ -51,11 +47,6 @@ SharedClassTable::SharedClassTable()
     table_[kVoidCid] = vm_shared_class_table->SizeAt(kVoidCid);
     table_[kNeverCid] = vm_shared_class_table->SizeAt(kNeverCid);
   }
-#if defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
-  unboxed_fields_map_ = static_cast<UnboxedFieldBitmap*>(
-      malloc(capacity_ * sizeof(UnboxedFieldBitmap)));
-  memset(unboxed_fields_map_, 0, sizeof(UnboxedFieldBitmap) * capacity_);
-#endif  // defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
 #ifndef PRODUCT
   trace_allocation_table_ =
       static_cast<uint8_t*>(malloc(capacity_ * sizeof(uint8_t)));  // NOLINT
@@ -70,16 +61,6 @@ SharedClassTable::~SharedClassTable() {
     delete old_tables_;
     free(table_);
   }
-
-  if (old_unboxed_fields_maps_ != nullptr) {
-    FreeOldUnboxedFieldsMaps();
-    delete old_unboxed_fields_maps_;
-  }
-
-  if (unboxed_fields_map_ != nullptr) {
-    free(unboxed_fields_map_);
-  }
-
   NOT_IN_PRODUCT(free(trace_allocation_table_));
 }
 
@@ -152,12 +133,6 @@ void SharedClassTable::FreeOldTables() {
   }
 }
 
-void SharedClassTable::FreeOldUnboxedFieldsMaps() {
-  while (old_unboxed_fields_maps_->length() > 0) {
-    free(old_unboxed_fields_maps_->RemoveLast());
-  }
-}
-
 void ClassTable::Register(const Class& cls) {
   ASSERT(Thread::Current()->IsMutatorThread());
 
@@ -167,7 +142,7 @@ void ClassTable::Register(const Class& cls) {
   // parallel to [ClassTable].
 
   const intptr_t instance_size =
-      cls.is_abstract() ? 0 : Class::host_instance_size(cls.raw());
+      cls.is_abstract() ? 0 : Class::instance_size(cls.raw());
 
   const intptr_t expected_cid =
       shared_class_table_->Register(index, instance_size);
@@ -264,7 +239,6 @@ void SharedClassTable::Grow(intptr_t new_capacity) {
 
   intptr_t* new_table = static_cast<intptr_t*>(
       malloc(new_capacity * sizeof(intptr_t)));  // NOLINT
-
   memmove(new_table, table_, top_ * sizeof(intptr_t));
   memset(new_table + top_, 0, (new_capacity - top_) * sizeof(intptr_t));
 #ifndef PRODUCT
@@ -276,22 +250,10 @@ void SharedClassTable::Grow(intptr_t new_capacity) {
     new_table[i] = 0;
     NOT_IN_PRODUCT(new_stats_table[i] = 0);
   }
-
   capacity_ = new_capacity;
   old_tables_->Add(table_);
   table_ = new_table;  // TODO(koda): This should use atomics.
   NOT_IN_PRODUCT(trace_allocation_table_ = new_stats_table);
-
-#if defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
-  auto new_unboxed_fields_map = static_cast<UnboxedFieldBitmap*>(
-      malloc(new_capacity * sizeof(UnboxedFieldBitmap)));
-  memmove(new_unboxed_fields_map, unboxed_fields_map_,
-          top_ * sizeof(UnboxedFieldBitmap));
-  memset(new_unboxed_fields_map + top_, 0,
-         (new_capacity - top_) * sizeof(UnboxedFieldBitmap));
-  old_unboxed_fields_maps_->Add(unboxed_fields_map_);
-  unboxed_fields_map_ = new_unboxed_fields_map;
-#endif  // defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
 }
 
 void ClassTable::Unregister(intptr_t index) {
@@ -301,9 +263,6 @@ void ClassTable::Unregister(intptr_t index) {
 
 void SharedClassTable::Unregister(intptr_t index) {
   table_[index] = 0;
-#if defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
-  unboxed_fields_map_[index].Reset();
-#endif  // defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
 }
 
 void ClassTable::Remap(intptr_t* old_to_new_cid) {
@@ -322,24 +281,14 @@ void ClassTable::Remap(intptr_t* old_to_new_cid) {
 void SharedClassTable::Remap(intptr_t* old_to_new_cid) {
   ASSERT(Thread::Current()->IsAtSafepoint());
   const intptr_t num_cids = NumCids();
-  std::unique_ptr<intptr_t[]> cls_by_old_cid(new intptr_t[num_cids]);
+  intptr_t* cls_by_old_cid = new intptr_t[num_cids];
   for (intptr_t i = 0; i < num_cids; i++) {
     cls_by_old_cid[i] = table_[i];
   }
   for (intptr_t i = 0; i < num_cids; i++) {
     table_[old_to_new_cid[i]] = cls_by_old_cid[i];
   }
-
-#if defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
-  std::unique_ptr<UnboxedFieldBitmap[]> unboxed_fields_by_old_cid(
-      new UnboxedFieldBitmap[num_cids]);
-  for (intptr_t i = 0; i < num_cids; i++) {
-    unboxed_fields_by_old_cid[i] = unboxed_fields_map_[i];
-  }
-  for (intptr_t i = 0; i < num_cids; i++) {
-    unboxed_fields_map_[old_to_new_cid[i]] = unboxed_fields_by_old_cid[i];
-  }
-#endif  // defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
+  delete[] cls_by_old_cid;
 }
 
 void ClassTable::VisitObjectPointers(ObjectPointerVisitor* visitor) {
@@ -395,8 +344,7 @@ void ClassTable::Print() {
 void ClassTable::SetAt(intptr_t index, RawClass* raw_cls) {
   // This is called by snapshot reader and class finalizer.
   ASSERT(index < capacity_);
-  const intptr_t size =
-      raw_cls == nullptr ? 0 : Class::host_instance_size(raw_cls);
+  const intptr_t size = raw_cls == nullptr ? 0 : Class::instance_size(raw_cls);
   shared_class_table_->SetSizeAt(index, size);
   table_[index] = raw_cls;
 }
diff --git a/runtime/vm/class_table.h b/runtime/vm/class_table.h
index 62383d3794ef6..fb13d2e481701 100644
--- a/runtime/vm/class_table.h
+++ b/runtime/vm/class_table.h
@@ -7,11 +7,9 @@
 
 #include "platform/assert.h"
 #include "platform/atomic.h"
-#include "platform/utils.h"
 
 #include "vm/bitfield.h"
 #include "vm/class_id.h"
-#include "vm/flags.h"
 #include "vm/globals.h"
 
 namespace dart {
@@ -30,33 +28,6 @@ class MallocGrowableArray;
 class ObjectPointerVisitor;
 class RawClass;
 
-// Wraps a 64-bit integer to represent the bitmap of unboxed fields
-// stored in the shared class table.
-class UnboxedFieldBitmap {
- public:
-  UnboxedFieldBitmap() : bitmap_(0) {}
-  explicit UnboxedFieldBitmap(uint64_t bitmap) : bitmap_(bitmap) {}
-  UnboxedFieldBitmap(const UnboxedFieldBitmap&) = default;
-  UnboxedFieldBitmap& operator=(const UnboxedFieldBitmap&) = default;
-
-  DART_FORCE_INLINE bool Get(intptr_t position) const {
-    return Utils::TestBit(bitmap_, position);
-  }
-  DART_FORCE_INLINE void Set(intptr_t position) {
-    bitmap_ |= Utils::Bit<decltype(bitmap_)>(position);
-  }
-  DART_FORCE_INLINE uint64_t Value() const { return bitmap_; }
-  DART_FORCE_INLINE bool IsEmpty() const { return bitmap_ == 0; }
-  DART_FORCE_INLINE void Reset() { bitmap_ = 0; }
-
-  DART_FORCE_INLINE static constexpr intptr_t Length() {
-    return sizeof(decltype(bitmap_)) * kBitsPerByte;
-  }
-
- private:
-  uint64_t bitmap_;
-};
-
 // Registry of all known classes and their sizes.
 //
 // The GC will only need the information in this shared class table to scan
@@ -91,19 +62,6 @@ class SharedClassTable {
   intptr_t NumCids() const { return top_; }
   intptr_t Capacity() const { return capacity_; }
 
-  UnboxedFieldBitmap GetUnboxedFieldsMapAt(intptr_t index) const {
-    ASSERT(IsValidIndex(index));
-    return FLAG_precompiled_mode ? unboxed_fields_map_[index]
-                                 : UnboxedFieldBitmap();
-  }
-
-  void SetUnboxedFieldsMapAt(intptr_t index,
-                             UnboxedFieldBitmap unboxed_fields_map) {
-    ASSERT(IsValidIndex(index));
-    ASSERT(unboxed_fields_map_[index].IsEmpty());
-    unboxed_fields_map_[index] = unboxed_fields_map;
-  }
-
   // Used to drop recently added classes.
   void SetNumCids(intptr_t num_cids) {
     ASSERT(num_cids <= top_);
@@ -159,9 +117,6 @@ class SharedClassTable {
   // Deallocates table copies. Do not call during concurrent access to table.
   void FreeOldTables();
 
-  // Deallocates bitmap copies. Do not call during concurrent access to table.
-  void FreeOldUnboxedFieldsMaps();
-
 #if !defined(DART_PRECOMPILED_RUNTIME)
   bool IsReloading() const { return reload_context_ != nullptr; }
 
@@ -216,14 +171,6 @@ class SharedClassTable {
 
   IsolateGroupReloadContext* reload_context_ = nullptr;
 
-  // Stores a 64-bit bitmap for each class. There is one bit for each word in an
-  // instance of the class. A 0 bit indicates that the word contains a pointer
-  // the GC has to scan, a 1 indicates that the word is part of e.g. an unboxed
-  // double and does not need to be scanned. (see Class::Calculate...() where
-  // the bitmap is constructed)
-  UnboxedFieldBitmap* unboxed_fields_map_;
-  MallocGrowableArray<UnboxedFieldBitmap*>* old_unboxed_fields_maps_;
-
   DISALLOW_COPY_AND_ASSIGN(SharedClassTable);
 };
 
diff --git a/runtime/vm/clustered_snapshot.cc b/runtime/vm/clustered_snapshot.cc
index 9dddd4c175593..50410b495d6ec 100644
--- a/runtime/vm/clustered_snapshot.cc
+++ b/runtime/vm/clustered_snapshot.cc
@@ -182,57 +182,19 @@ class ClassSerializationCluster : public SerializationCluster {
     if (s->kind() != Snapshot::kFullAOT) {
       s->Write<uint32_t>(cls->ptr()->binary_declaration_);
     }
-    s->Write<int32_t>(Class::target_instance_size_in_words(cls));
-    s->Write<int32_t>(Class::target_next_field_offset_in_words(cls));
-    s->Write<int32_t>(Class::target_type_arguments_field_offset_in_words(cls));
+    s->Write<int32_t>(cls->ptr()->instance_size_in_words_);
+    s->Write<int32_t>(cls->ptr()->next_field_offset_in_words_);
+    s->Write<int32_t>(cls->ptr()->type_arguments_field_offset_in_words_);
     s->Write<int16_t>(cls->ptr()->num_type_arguments_);
     s->Write<uint16_t>(cls->ptr()->num_native_fields_);
     s->WriteTokenPosition(cls->ptr()->token_pos_);
     s->WriteTokenPosition(cls->ptr()->end_token_pos_);
     s->Write<uint32_t>(cls->ptr()->state_bits_);
-
-    // In AOT, the bitmap of unboxed fields should also be serialized
-    if (FLAG_precompiled_mode) {
-      s->WriteUnsigned64(
-          CalculateTargetUnboxedFieldsBitmap(s, class_id).Value());
-    }
   }
 
  private:
   GrowableArray<RawClass*> predefined_;
   GrowableArray<RawClass*> objects_;
-
-  UnboxedFieldBitmap CalculateTargetUnboxedFieldsBitmap(Serializer* s,
-                                                        intptr_t class_id) {
-    const auto unboxed_fields_bitmap_host =
-        s->isolate()->shared_class_table()->GetUnboxedFieldsMapAt(class_id);
-
-    UnboxedFieldBitmap unboxed_fields_bitmap;
-    if (unboxed_fields_bitmap_host.IsEmpty() ||
-        kWordSize == compiler::target::kWordSize) {
-      unboxed_fields_bitmap = unboxed_fields_bitmap_host;
-    } else {
-      ASSERT(kWordSize == 8 && compiler::target::kWordSize == 4);
-      // A new bitmap is built if the word sizes in the target and
-      // host are different
-      unboxed_fields_bitmap.Reset();
-      intptr_t target_i = 0, host_i = 0;
-
-      while (host_i < UnboxedFieldBitmap::Length()) {
-        // Each unboxed field has constant length, therefore the number of
-        // words used by it should double when compiling from 64-bit to 32-bit.
-        if (unboxed_fields_bitmap_host.Get(host_i++)) {
-          unboxed_fields_bitmap.Set(target_i++);
-          unboxed_fields_bitmap.Set(target_i++);
-        } else {
-          // For object pointers, the field is always one word length
-          target_i++;
-        }
-      }
-    }
-
-    return unboxed_fields_bitmap;
-  }
 };
 #endif  // !DART_PRECOMPILED_RUNTIME
 
@@ -278,35 +240,18 @@ class ClassDeserializationCluster : public DeserializationCluster {
       }
 #endif
       if (!RawObject::IsInternalVMdefinedClassId(class_id)) {
-        cls->ptr()->host_instance_size_in_words_ = d->Read<int32_t>();
-        cls->ptr()->host_next_field_offset_in_words_ = d->Read<int32_t>();
-#if !defined(DART_PRECOMPILED_RUNTIME)
-        // Only one pair is serialized. The target field only exists when
-        // DART_PRECOMPILED_RUNTIME is not defined
-        cls->ptr()->target_instance_size_in_words_ =
-            cls->ptr()->host_instance_size_in_words_;
-        cls->ptr()->target_next_field_offset_in_words_ =
-            cls->ptr()->host_next_field_offset_in_words_;
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+        cls->ptr()->instance_size_in_words_ = d->Read<int32_t>();
+        cls->ptr()->next_field_offset_in_words_ = d->Read<int32_t>();
       } else {
         d->Read<int32_t>();  // Skip.
         d->Read<int32_t>();  // Skip.
       }
-      cls->ptr()->host_type_arguments_field_offset_in_words_ =
-          d->Read<int32_t>();
-#if !defined(DART_PRECOMPILED_RUNTIME)
-      cls->ptr()->target_type_arguments_field_offset_in_words_ =
-          cls->ptr()->host_type_arguments_field_offset_in_words_;
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+      cls->ptr()->type_arguments_field_offset_in_words_ = d->Read<int32_t>();
       cls->ptr()->num_type_arguments_ = d->Read<int16_t>();
       cls->ptr()->num_native_fields_ = d->Read<uint16_t>();
       cls->ptr()->token_pos_ = d->ReadTokenPosition();
       cls->ptr()->end_token_pos_ = d->ReadTokenPosition();
       cls->ptr()->state_bits_ = d->Read<uint32_t>();
-
-      if (FLAG_precompiled_mode) {
-        d->ReadUnsigned64();  // Skip unboxed fields bitmap.
-      }
     }
 
     for (intptr_t id = start_index_; id < stop_index_; id++) {
@@ -323,18 +268,9 @@ class ClassDeserializationCluster : public DeserializationCluster {
         cls->ptr()->binary_declaration_ = d->Read<uint32_t>();
       }
 #endif
-      cls->ptr()->host_instance_size_in_words_ = d->Read<int32_t>();
-      cls->ptr()->host_next_field_offset_in_words_ = d->Read<int32_t>();
-      cls->ptr()->host_type_arguments_field_offset_in_words_ =
-          d->Read<int32_t>();
-#if !defined(DART_PRECOMPILED_RUNTIME)
-      cls->ptr()->target_instance_size_in_words_ =
-          cls->ptr()->host_instance_size_in_words_;
-      cls->ptr()->target_next_field_offset_in_words_ =
-          cls->ptr()->host_next_field_offset_in_words_;
-      cls->ptr()->target_type_arguments_field_offset_in_words_ =
-          cls->ptr()->host_type_arguments_field_offset_in_words_;
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+      cls->ptr()->instance_size_in_words_ = d->Read<int32_t>();
+      cls->ptr()->next_field_offset_in_words_ = d->Read<int32_t>();
+      cls->ptr()->type_arguments_field_offset_in_words_ = d->Read<int32_t>();
       cls->ptr()->num_type_arguments_ = d->Read<int16_t>();
       cls->ptr()->num_native_fields_ = d->Read<uint16_t>();
       cls->ptr()->token_pos_ = d->ReadTokenPosition();
@@ -343,12 +279,6 @@ class ClassDeserializationCluster : public DeserializationCluster {
 
       table->AllocateIndex(class_id);
       table->SetAt(class_id, cls);
-
-      if (FLAG_precompiled_mode) {
-        const UnboxedFieldBitmap unboxed_fields_map(d->ReadUnsigned64());
-        d->isolate()->shared_class_table()->SetUnboxedFieldsMapAt(
-            class_id, unboxed_fields_map);
-      }
     }
   }
 
@@ -1005,13 +935,13 @@ class FieldSerializationCluster : public SerializationCluster {
           kind == Snapshot::kFullAOT ||
           // Do not reset const fields.
           Field::ConstBit::decode(field->ptr()->kind_bits_)) {
-        s->Push(s->field_table()->At(field->ptr()->host_offset_or_field_id_));
+        s->Push(s->field_table()->At(field->ptr()->offset_or_field_id_));
       } else {
         // Otherwise, for static fields we write out the initial static value.
         s->Push(field->ptr()->saved_initial_value_);
       }
     } else {
-      s->Push(Smi::New(Field::TargetOffsetOf(field)));
+      s->Push(Smi::New(field->ptr()->offset_or_field_id_));
     }
   }
 
@@ -1071,14 +1001,14 @@ class FieldSerializationCluster : public SerializationCluster {
             Field::ConstBit::decode(field->ptr()->kind_bits_)) {
           WriteFieldValue(
               "static value",
-              s->field_table()->At(field->ptr()->host_offset_or_field_id_));
+              s->field_table()->At(field->ptr()->offset_or_field_id_));
         } else {
           // Otherwise, for static fields we write out the initial static value.
           WriteFieldValue("static value", field->ptr()->saved_initial_value_);
         }
-        s->WriteUnsigned(field->ptr()->host_offset_or_field_id_);
+        s->WriteUnsigned(field->ptr()->offset_or_field_id_);
       } else {
-        WriteFieldValue("offset", Smi::New(Field::TargetOffsetOf(field)));
+        WriteFieldValue("offset", Smi::New(field->ptr()->offset_or_field_id_));
       }
     }
   }
@@ -1127,13 +1057,10 @@ class FieldDeserializationCluster : public DeserializationCluster {
         intptr_t field_id = d->ReadUnsigned();
         d->field_table()->SetAt(
             field_id, reinterpret_cast<RawInstance*>(value_or_offset));
-        field->ptr()->host_offset_or_field_id_ = field_id;
+        field->ptr()->offset_or_field_id_ = field_id;
       } else {
-        field->ptr()->host_offset_or_field_id_ =
+        field->ptr()->offset_or_field_id_ =
             Smi::Value(Smi::RawCast(value_or_offset));
-#if !defined(DART_PRECOMPILED_RUNTIME)
-        field->ptr()->target_offset_ = field->ptr()->host_offset_or_field_id_;
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
       }
     }
   }
@@ -2795,34 +2722,23 @@ class InstanceSerializationCluster : public SerializationCluster {
   explicit InstanceSerializationCluster(intptr_t cid)
       : SerializationCluster("Instance"), cid_(cid) {
     RawClass* cls = Isolate::Current()->class_table()->At(cid);
-    host_next_field_offset_in_words_ =
-        cls->ptr()->host_next_field_offset_in_words_;
-    ASSERT(host_next_field_offset_in_words_ > 0);
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    target_next_field_offset_in_words_ =
-        cls->ptr()->target_next_field_offset_in_words_;
-    target_instance_size_in_words_ = cls->ptr()->target_instance_size_in_words_;
-    ASSERT(target_next_field_offset_in_words_ > 0);
-    ASSERT(target_instance_size_in_words_ > 0);
-#endif  // !defined(DART_PRECOMPILED_RUNTIME)
+    next_field_offset_in_words_ = cls->ptr()->next_field_offset_in_words_;
+    instance_size_in_words_ = cls->ptr()->instance_size_in_words_;
+    ASSERT(next_field_offset_in_words_ > 0);
+    ASSERT(instance_size_in_words_ > 0);
   }
   ~InstanceSerializationCluster() {}
 
   void Trace(Serializer* s, RawObject* object) {
     RawInstance* instance = Instance::RawCast(object);
     objects_.Add(instance);
-    const intptr_t next_field_offset = host_next_field_offset_in_words_
-                                       << kWordSizeLog2;
-    const auto unboxed_fields_bitmap =
-        s->isolate()->shared_class_table()->GetUnboxedFieldsMapAt(cid_);
+
+    intptr_t next_field_offset = next_field_offset_in_words_ << kWordSizeLog2;
     intptr_t offset = Instance::NextFieldOffset();
     while (offset < next_field_offset) {
-      // Skips unboxed fields
-      if (!unboxed_fields_bitmap.Get(offset / kWordSize)) {
-        RawObject* raw_obj = *reinterpret_cast<RawObject**>(
-            reinterpret_cast<uword>(instance->ptr()) + offset);
-        s->Push(raw_obj);
-      }
+      RawObject* raw_obj = *reinterpret_cast<RawObject**>(
+          reinterpret_cast<uword>(instance->ptr()) + offset);
+      s->Push(raw_obj);
       offset += kWordSize;
     }
   }
@@ -2832,12 +2748,8 @@ class InstanceSerializationCluster : public SerializationCluster {
     const intptr_t count = objects_.length();
     s->WriteUnsigned(count);
 
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    s->Write<int32_t>(target_next_field_offset_in_words_);
-    s->Write<int32_t>(target_instance_size_in_words_);
-#else
-    s->Write<int32_t>(host_next_field_offset_in_words_);
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+    s->Write<int32_t>(next_field_offset_in_words_);
+    s->Write<int32_t>(instance_size_in_words_);
 
     for (intptr_t i = 0; i < count; i++) {
       RawInstance* instance = objects_[i];
@@ -2846,28 +2758,17 @@ class InstanceSerializationCluster : public SerializationCluster {
   }
 
   void WriteFill(Serializer* s) {
-    intptr_t next_field_offset = host_next_field_offset_in_words_
-                                 << kWordSizeLog2;
+    intptr_t next_field_offset = next_field_offset_in_words_ << kWordSizeLog2;
     const intptr_t count = objects_.length();
-    const auto shared_class_table = s->isolate()->shared_class_table();
     for (intptr_t i = 0; i < count; i++) {
       RawInstance* instance = objects_[i];
       AutoTraceObject(instance);
       s->Write<bool>(instance->IsCanonical());
-      const auto unboxed_fields_bitmap =
-          shared_class_table->GetUnboxedFieldsMapAt(cid_);
       intptr_t offset = Instance::NextFieldOffset();
       while (offset < next_field_offset) {
-        if (unboxed_fields_bitmap.Get(offset / kWordSize)) {
-          // Writes 32 bits of the unboxed value at a time
-          const uword value = *reinterpret_cast<uword*>(
-              reinterpret_cast<uword>(instance->ptr()) + offset);
-          s->WriteWordWith32BitWrites(value);
-        } else {
-          RawObject* raw_obj = *reinterpret_cast<RawObject**>(
-              reinterpret_cast<uword>(instance->ptr()) + offset);
-          s->WriteElementRef(raw_obj, offset);
-        }
+        RawObject* raw_obj = *reinterpret_cast<RawObject**>(
+            reinterpret_cast<uword>(instance->ptr()) + offset);
+        s->WriteElementRef(raw_obj, offset);
         offset += kWordSize;
       }
     }
@@ -2875,11 +2776,8 @@ class InstanceSerializationCluster : public SerializationCluster {
 
  private:
   const intptr_t cid_;
-  intptr_t host_next_field_offset_in_words_;
-#if !defined(DART_PRECOMPILED_RUNTIME)
-  intptr_t target_next_field_offset_in_words_;
-  intptr_t target_instance_size_in_words_;
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+  intptr_t next_field_offset_in_words_;
+  intptr_t instance_size_in_words_;
   GrowableArray<RawInstance*> objects_;
 };
 #endif  // !DART_PRECOMPILED_RUNTIME
@@ -2908,26 +2806,16 @@ class InstanceDeserializationCluster : public DeserializationCluster {
     intptr_t instance_size =
         Object::RoundedAllocationSize(instance_size_in_words_ * kWordSize);
 
-    const auto shared_class_table = d->isolate()->shared_class_table();
     for (intptr_t id = start_index_; id < stop_index_; id++) {
       RawInstance* instance = reinterpret_cast<RawInstance*>(d->Ref(id));
       bool is_canonical = d->Read<bool>();
       Deserializer::InitializeHeader(instance, cid_, instance_size,
                                      is_canonical);
-      const auto unboxed_fields_bitmap =
-          shared_class_table->GetUnboxedFieldsMapAt(cid_);
       intptr_t offset = Instance::NextFieldOffset();
       while (offset < next_field_offset) {
-        if (unboxed_fields_bitmap.Get(offset / kWordSize)) {
-          uword* p = reinterpret_cast<uword*>(
-              reinterpret_cast<uword>(instance->ptr()) + offset);
-          // Reads 32 bits of the unboxed value at a time
-          *p = d->ReadWordWith32BitReads();
-        } else {
-          RawObject** p = reinterpret_cast<RawObject**>(
-              reinterpret_cast<uword>(instance->ptr()) + offset);
-          *p = d->ReadRef();
-        }
+        RawObject** p = reinterpret_cast<RawObject**>(
+            reinterpret_cast<uword>(instance->ptr()) + offset);
+        *p = d->ReadRef();
         offset += kWordSize;
       }
       if (offset < instance_size) {
diff --git a/runtime/vm/clustered_snapshot.h b/runtime/vm/clustered_snapshot.h
index ed8555fd4128c..7be84ef2d046e 100644
--- a/runtime/vm/clustered_snapshot.h
+++ b/runtime/vm/clustered_snapshot.h
@@ -234,12 +234,6 @@ class Serializer : public ThreadStackResource {
     WriteStream::Raw<sizeof(T), T>::Write(&stream_, value);
   }
   void WriteUnsigned(intptr_t value) { stream_.WriteUnsigned(value); }
-  void WriteUnsigned64(uint64_t value) { stream_.WriteUnsigned(value); }
-
-  void WriteWordWith32BitWrites(uword value) {
-    stream_.WriteWordWith32BitWrites(value);
-  }
-
   void WriteBytes(const uint8_t* addr, intptr_t len) {
     stream_.WriteBytes(addr, len);
   }
@@ -502,11 +496,8 @@ class Deserializer : public ThreadStackResource {
     return ReadStream::Raw<sizeof(T), T>::Read(&stream_);
   }
   intptr_t ReadUnsigned() { return stream_.ReadUnsigned(); }
-  uint64_t ReadUnsigned64() { return stream_.ReadUnsigned<uint64_t>(); }
   void ReadBytes(uint8_t* addr, intptr_t len) { stream_.ReadBytes(addr, len); }
 
-  uword ReadWordWith32BitReads() { return stream_.ReadWordWith32BitReads(); }
-
   const uint8_t* CurrentBufferAddress() const {
     return stream_.AddressOfCurrentPosition();
   }
diff --git a/runtime/vm/compiler/backend/il.h b/runtime/vm/compiler/backend/il.h
index cbbc454219704..4213e64235715 100644
--- a/runtime/vm/compiler/backend/il.h
+++ b/runtime/vm/compiler/backend/il.h
@@ -5498,7 +5498,7 @@ class AllocateObjectInstr : public AllocationInstr {
   }
 
   static bool WillAllocateNewOrRemembered(const Class& cls) {
-    return Heap::IsAllocatableInNewSpace(cls.target_instance_size());
+    return Heap::IsAllocatableInNewSpace(cls.instance_size());
   }
 
   PRINT_OPERANDS_TO_SUPPORT
diff --git a/runtime/vm/compiler/backend/il_arm.cc b/runtime/vm/compiler/backend/il_arm.cc
index 235b68331efe8..6c43554b4255e 100644
--- a/runtime/vm/compiler/backend/il_arm.cc
+++ b/runtime/vm/compiler/backend/il_arm.cc
@@ -2557,8 +2557,7 @@ LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary(Zone* zone,
                                                               bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps =
-      ((IsUnboxedStore() && opt) ? (FLAG_precompiled_mode ? 0 : 2)
-                                 : (IsPotentialUnboxedStore() ? 3 : 0));
+      ((IsUnboxedStore() && opt) ? 2 : ((IsPotentialUnboxedStore()) ? 3 : 0));
   LocationSummary* summary = new (zone)
       LocationSummary(zone, kNumInputs, kNumTemps,
                       ((IsUnboxedStore() && opt && is_initialization()) ||
@@ -2569,10 +2568,8 @@ LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary(Zone* zone,
   summary->set_in(0, Location::RequiresRegister());
   if (IsUnboxedStore() && opt) {
     summary->set_in(1, Location::RequiresFpuRegister());
-    if (!FLAG_precompiled_mode) {
-      summary->set_temp(0, Location::RequiresRegister());
-      summary->set_temp(1, Location::RequiresRegister());
-    }
+    summary->set_temp(0, Location::RequiresRegister());
+    summary->set_temp(1, Location::RequiresRegister());
   } else if (IsPotentialUnboxedStore()) {
     summary->set_in(1, ShouldEmitStoreBarrier() ? Location::WritableRegister()
                                                 : Location::RequiresRegister());
@@ -2618,33 +2615,10 @@ void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(offset_in_bytes > 0);  // Field is finalized and points after header.
 
   if (IsUnboxedStore() && compiler->is_optimizing()) {
-    const intptr_t cid = slot().field().UnboxedFieldCid();
     const DRegister value = EvenDRegisterOf(locs()->in(1).fpu_reg());
-
-    if (FLAG_precompiled_mode) {
-      switch (cid) {
-        case kDoubleCid:
-          __ Comment("UnboxedDoubleStoreInstanceFieldInstr");
-          __ StoreDToOffset(value, instance_reg,
-                            offset_in_bytes - kHeapObjectTag);
-          return;
-        case kFloat32x4Cid:
-          __ Comment("UnboxedFloat32x4StoreInstanceFieldInstr");
-          __ StoreMultipleDToOffset(value, 2, instance_reg,
-                                    offset_in_bytes - kHeapObjectTag);
-          return;
-        case kFloat64x2Cid:
-          __ Comment("UnboxedFloat64x2StoreInstanceFieldInstr");
-          __ StoreMultipleDToOffset(value, 2, instance_reg,
-                                    offset_in_bytes - kHeapObjectTag);
-          return;
-        default:
-          UNREACHABLE();
-      }
-    }
-
     const Register temp = locs()->temp(0).reg();
     const Register temp2 = locs()->temp(1).reg();
+    const intptr_t cid = slot().field().UnboxedFieldCid();
 
     if (is_initialization()) {
       const Class* cls = NULL;
@@ -2989,9 +2963,8 @@ void CreateArrayInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 LocationSummary* LoadFieldInstr::MakeLocationSummary(Zone* zone,
                                                      bool opt) const {
   const intptr_t kNumInputs = 1;
-  const intptr_t kNumTemps = (IsUnboxedLoad() && opt)
-                                 ? (FLAG_precompiled_mode ? 0 : 1)
-                                 : (IsPotentialUnboxedLoad() ? 3 : 0);
+  const intptr_t kNumTemps =
+      (IsUnboxedLoad() && opt) ? 1 : ((IsPotentialUnboxedLoad()) ? 3 : 0);
 
   LocationSummary* locs = new (zone) LocationSummary(
       zone, kNumInputs, kNumTemps,
@@ -3001,9 +2974,7 @@ LocationSummary* LoadFieldInstr::MakeLocationSummary(Zone* zone,
   locs->set_in(0, Location::RequiresRegister());
 
   if (IsUnboxedLoad() && opt) {
-    if (!FLAG_precompiled_mode) {
-      locs->set_temp(0, Location::RequiresRegister());
-    }
+    locs->set_temp(0, Location::RequiresRegister());
   } else if (IsPotentialUnboxedLoad()) {
     locs->set_temp(0, opt ? Location::RequiresFpuRegister()
                           : Location::FpuRegisterLocation(Q1));
@@ -3019,33 +2990,10 @@ void LoadFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
   const Register instance_reg = locs()->in(0).reg();
   if (IsUnboxedLoad() && compiler->is_optimizing()) {
-    const intptr_t cid = slot().field().UnboxedFieldCid();
     const DRegister result = EvenDRegisterOf(locs()->out(0).fpu_reg());
-
-    if (FLAG_precompiled_mode) {
-      switch (cid) {
-        case kDoubleCid:
-          __ Comment("UnboxedDoubleLoadFieldInstr");
-          __ LoadDFromOffset(result, instance_reg,
-                             OffsetInBytes() - kHeapObjectTag);
-          return;
-        case kFloat32x4Cid:
-          __ Comment("UnboxedFloat32x4LoadFieldInstr");
-          __ LoadMultipleDFromOffset(result, 2, instance_reg,
-                                     OffsetInBytes() - kHeapObjectTag);
-          return;
-        case kFloat64x2Cid:
-          __ Comment("UnboxedFloat64x2LoadFieldInstr");
-          __ LoadMultipleDFromOffset(result, 2, instance_reg,
-                                     OffsetInBytes() - kHeapObjectTag);
-          return;
-        default:
-          UNREACHABLE();
-      }
-    }
-
     const Register temp = locs()->temp(0).reg();
     __ LoadFieldFromOffset(kWord, temp, instance_reg, OffsetInBytes());
+    const intptr_t cid = slot().field().UnboxedFieldCid();
     switch (cid) {
       case kDoubleCid:
         __ Comment("UnboxedDoubleLoadFieldInstr");
@@ -3372,7 +3320,7 @@ void InitInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register temp = locs()->temp(0).reg();
   compiler::Label no_call;
 
-  __ ldr(temp, compiler::FieldAddress(instance, field().TargetOffset()));
+  __ ldr(temp, compiler::FieldAddress(instance, field().Offset()));
   __ CompareObject(temp, Object::sentinel());
   __ b(&no_call, NE);
 
diff --git a/runtime/vm/compiler/backend/il_arm64.cc b/runtime/vm/compiler/backend/il_arm64.cc
index 9894048837940..405bc328dde98 100644
--- a/runtime/vm/compiler/backend/il_arm64.cc
+++ b/runtime/vm/compiler/backend/il_arm64.cc
@@ -2158,9 +2158,8 @@ static void EnsureMutableBox(FlowGraphCompiler* compiler,
 LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary(Zone* zone,
                                                               bool opt) const {
   const intptr_t kNumInputs = 2;
-  const intptr_t kNumTemps = (IsUnboxedStore() && opt)
-                                 ? (FLAG_precompiled_mode ? 0 : 2)
-                                 : (IsPotentialUnboxedStore() ? 2 : 0);
+  const intptr_t kNumTemps =
+      (IsUnboxedStore() && opt) ? 2 : ((IsPotentialUnboxedStore()) ? 2 : 0);
   LocationSummary* summary = new (zone)
       LocationSummary(zone, kNumInputs, kNumTemps,
                       ((IsUnboxedStore() && opt && is_initialization()) ||
@@ -2171,10 +2170,8 @@ LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary(Zone* zone,
   summary->set_in(0, Location::RequiresRegister());
   if (IsUnboxedStore() && opt) {
     summary->set_in(1, Location::RequiresFpuRegister());
-    if (!FLAG_precompiled_mode) {
-      summary->set_temp(0, Location::RequiresRegister());
-      summary->set_temp(1, Location::RequiresRegister());
-    }
+    summary->set_temp(0, Location::RequiresRegister());
+    summary->set_temp(1, Location::RequiresRegister());
   } else if (IsPotentialUnboxedStore()) {
     summary->set_in(1, ShouldEmitStoreBarrier() ? Location::WritableRegister()
                                                 : Location::RequiresRegister());
@@ -2198,29 +2195,9 @@ void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
   if (IsUnboxedStore() && compiler->is_optimizing()) {
     const VRegister value = locs()->in(1).fpu_reg();
-    const intptr_t cid = slot().field().UnboxedFieldCid();
-
-    if (FLAG_precompiled_mode) {
-      switch (cid) {
-        case kDoubleCid:
-          __ Comment("UnboxedDoubleStoreInstanceFieldInstr");
-          __ StoreDFieldToOffset(value, instance_reg, offset_in_bytes);
-          return;
-        case kFloat32x4Cid:
-          __ Comment("UnboxedFloat32x4StoreInstanceFieldInstr");
-          __ StoreQFieldToOffset(value, instance_reg, offset_in_bytes);
-          return;
-        case kFloat64x2Cid:
-          __ Comment("UnboxedFloat64x2StoreInstanceFieldInstr");
-          __ StoreQFieldToOffset(value, instance_reg, offset_in_bytes);
-          return;
-        default:
-          UNREACHABLE();
-      }
-    }
-
     const Register temp = locs()->temp(0).reg();
     const Register temp2 = locs()->temp(1).reg();
+    const intptr_t cid = slot().field().UnboxedFieldCid();
 
     if (is_initialization()) {
       const Class* cls = NULL;
@@ -2557,9 +2534,8 @@ void CreateArrayInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 LocationSummary* LoadFieldInstr::MakeLocationSummary(Zone* zone,
                                                      bool opt) const {
   const intptr_t kNumInputs = 1;
-  const intptr_t kNumTemps = (IsUnboxedLoad() && opt)
-                                 ? (FLAG_precompiled_mode ? 0 : 1)
-                                 : (IsPotentialUnboxedLoad() ? 1 : 0);
+  const intptr_t kNumTemps =
+      (IsUnboxedLoad() && opt) ? 1 : ((IsPotentialUnboxedLoad()) ? 1 : 0);
   LocationSummary* locs = new (zone) LocationSummary(
       zone, kNumInputs, kNumTemps,
       (opt && !IsPotentialUnboxedLoad()) ? LocationSummary::kNoCall
@@ -2568,9 +2544,7 @@ LocationSummary* LoadFieldInstr::MakeLocationSummary(Zone* zone,
   locs->set_in(0, Location::RequiresRegister());
 
   if (IsUnboxedLoad() && opt) {
-    if (!FLAG_precompiled_mode) {
-      locs->set_temp(0, Location::RequiresRegister());
-    }
+    locs->set_temp(0, Location::RequiresRegister());
   } else if (IsPotentialUnboxedLoad()) {
     locs->set_temp(0, Location::RequiresRegister());
   }
@@ -2583,30 +2557,9 @@ void LoadFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   const Register instance_reg = locs()->in(0).reg();
   if (IsUnboxedLoad() && compiler->is_optimizing()) {
     const VRegister result = locs()->out(0).fpu_reg();
-    const intptr_t cid = slot().field().UnboxedFieldCid();
-
-    if (FLAG_precompiled_mode) {
-      switch (cid) {
-        case kDoubleCid:
-          __ Comment("UnboxedDoubleLoadFieldInstr");
-          __ LoadDFieldFromOffset(result, instance_reg, OffsetInBytes());
-          return;
-        case kFloat32x4Cid:
-          __ Comment("UnboxedFloat32x4LoadFieldInstr");
-          __ LoadQFieldFromOffset(result, instance_reg, OffsetInBytes());
-          return;
-        case kFloat64x2Cid:
-          __ Comment("UnboxedFloat64x2LoadFieldInstr");
-          __ LoadQFieldFromOffset(result, instance_reg, OffsetInBytes());
-          return;
-        default:
-          UNREACHABLE();
-      }
-    }
-
     const Register temp = locs()->temp(0).reg();
-
     __ LoadFieldFromOffset(temp, instance_reg, OffsetInBytes());
+    const intptr_t cid = slot().field().UnboxedFieldCid();
     switch (cid) {
       case kDoubleCid:
         __ Comment("UnboxedDoubleLoadFieldInstr");
@@ -2922,7 +2875,7 @@ void InitInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register temp = locs()->temp(0).reg();
   compiler::Label no_call;
 
-  __ ldr(temp, compiler::FieldAddress(instance, field().TargetOffset()));
+  __ ldr(temp, compiler::FieldAddress(instance, field().Offset()));
   __ CompareObject(temp, Object::sentinel());
   __ b(&no_call, NE);
 
diff --git a/runtime/vm/compiler/backend/il_ia32.cc b/runtime/vm/compiler/backend/il_ia32.cc
index 28a4d5969fb18..c02b5e710a55d 100644
--- a/runtime/vm/compiler/backend/il_ia32.cc
+++ b/runtime/vm/compiler/backend/il_ia32.cc
@@ -2753,7 +2753,7 @@ void InitInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
   compiler::Label no_call;
 
-  __ movl(temp, compiler::FieldAddress(instance, field().TargetOffset()));
+  __ movl(temp, compiler::FieldAddress(instance, field().Offset()));
   __ CompareObject(temp, Object::sentinel());
   __ j(NOT_EQUAL, &no_call, compiler::Assembler::kNearJump);
 
diff --git a/runtime/vm/compiler/backend/il_serializer.cc b/runtime/vm/compiler/backend/il_serializer.cc
index b8739924913a4..2ec431aeb294d 100644
--- a/runtime/vm/compiler/backend/il_serializer.cc
+++ b/runtime/vm/compiler/backend/il_serializer.cc
@@ -1308,7 +1308,7 @@ void AllocateObjectInstr::AddExtraInfoToSExpression(
     SExpList* sexp,
     FlowGraphSerializer* s) const {
   Instruction::AddExtraInfoToSExpression(sexp, s);
-  s->AddExtraInteger(sexp, "size", cls().target_instance_size());
+  s->AddExtraInteger(sexp, "size", cls().instance_size());
   if (auto const closure = s->DartValueToSExp(closure_function())) {
     sexp->AddExtra("closure_function", closure);
   }
diff --git a/runtime/vm/compiler/backend/il_x64.cc b/runtime/vm/compiler/backend/il_x64.cc
index 9af1adc9272a8..4b9cfcde11a91 100644
--- a/runtime/vm/compiler/backend/il_x64.cc
+++ b/runtime/vm/compiler/backend/il_x64.cc
@@ -2128,9 +2128,8 @@ void GuardFieldTypeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary(Zone* zone,
                                                               bool opt) const {
   const intptr_t kNumInputs = 2;
-  const intptr_t kNumTemps = (IsUnboxedStore() && opt)
-                                 ? (FLAG_precompiled_mode ? 0 : 2)
-                                 : (IsPotentialUnboxedStore() ? 3 : 0);
+  const intptr_t kNumTemps =
+      (IsUnboxedStore() && opt) ? 2 : ((IsPotentialUnboxedStore()) ? 3 : 0);
   LocationSummary* summary = new (zone)
       LocationSummary(zone, kNumInputs, kNumTemps,
                       ((IsUnboxedStore() && opt && is_initialization()) ||
@@ -2141,10 +2140,8 @@ LocationSummary* StoreInstanceFieldInstr::MakeLocationSummary(Zone* zone,
   summary->set_in(0, Location::RequiresRegister());
   if (IsUnboxedStore() && opt) {
     summary->set_in(1, Location::RequiresFpuRegister());
-    if (!FLAG_precompiled_mode) {
-      summary->set_temp(0, Location::RequiresRegister());
-      summary->set_temp(1, Location::RequiresRegister());
-    }
+    summary->set_temp(0, Location::RequiresRegister());
+    summary->set_temp(1, Location::RequiresRegister());
   } else if (IsPotentialUnboxedStore()) {
     summary->set_in(1, ShouldEmitStoreBarrier() ? Location::WritableRegister()
                                                 : Location::RequiresRegister());
@@ -2189,33 +2186,9 @@ void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
   if (IsUnboxedStore() && compiler->is_optimizing()) {
     XmmRegister value = locs()->in(1).fpu_reg();
-    const intptr_t cid = slot().field().UnboxedFieldCid();
-
-    // Real unboxed field
-    if (FLAG_precompiled_mode) {
-      switch (cid) {
-        case kDoubleCid:
-          __ Comment("UnboxedDoubleStoreInstanceFieldInstr");
-          __ movsd(compiler::FieldAddress(instance_reg, offset_in_bytes),
-                   value);
-          return;
-        case kFloat32x4Cid:
-          __ Comment("UnboxedFloat32x4StoreInstanceFieldInstr");
-          __ movups(compiler::FieldAddress(instance_reg, offset_in_bytes),
-                    value);
-          return;
-        case kFloat64x2Cid:
-          __ Comment("UnboxedFloat64x2StoreInstanceFieldInstr");
-          __ movups(compiler::FieldAddress(instance_reg, offset_in_bytes),
-                    value);
-          return;
-        default:
-          UNREACHABLE();
-      }
-    }
-
     Register temp = locs()->temp(0).reg();
     Register temp2 = locs()->temp(1).reg();
+    const intptr_t cid = slot().field().UnboxedFieldCid();
 
     if (is_initialization()) {
       const Class* cls = NULL;
@@ -2560,9 +2533,8 @@ void CreateArrayInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 LocationSummary* LoadFieldInstr::MakeLocationSummary(Zone* zone,
                                                      bool opt) const {
   const intptr_t kNumInputs = 1;
-  const intptr_t kNumTemps = (IsUnboxedLoad() && opt)
-                                 ? (FLAG_precompiled_mode ? 0 : 1)
-                                 : (IsPotentialUnboxedLoad() ? 2 : 0);
+  const intptr_t kNumTemps =
+      (IsUnboxedLoad() && opt) ? 1 : ((IsPotentialUnboxedLoad()) ? 2 : 0);
   LocationSummary* locs = new (zone) LocationSummary(
       zone, kNumInputs, kNumTemps,
       (opt && !IsPotentialUnboxedLoad()) ? LocationSummary::kNoCall
@@ -2571,9 +2543,7 @@ LocationSummary* LoadFieldInstr::MakeLocationSummary(Zone* zone,
   locs->set_in(0, Location::RequiresRegister());
 
   if (IsUnboxedLoad() && opt) {
-    if (!FLAG_precompiled_mode) {
-      locs->set_temp(0, Location::RequiresRegister());
-    }
+    locs->set_temp(0, Location::RequiresRegister());
   } else if (IsPotentialUnboxedLoad()) {
     locs->set_temp(0, opt ? Location::RequiresFpuRegister()
                           : Location::FpuRegisterLocation(XMM1));
@@ -2588,34 +2558,9 @@ void LoadFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register instance_reg = locs()->in(0).reg();
   if (IsUnboxedLoad() && compiler->is_optimizing()) {
     XmmRegister result = locs()->out(0).fpu_reg();
-    const intptr_t cid = slot().field().UnboxedFieldCid();
-
-    // Real unboxed field
-    if (FLAG_precompiled_mode) {
-      switch (cid) {
-        case kDoubleCid:
-          __ Comment("UnboxedDoubleLoadFieldInstr");
-          __ movsd(result,
-                   compiler::FieldAddress(instance_reg, OffsetInBytes()));
-          break;
-        case kFloat32x4Cid:
-          __ Comment("UnboxedFloat32x4LoadFieldInstr");
-          __ movups(result,
-                    compiler::FieldAddress(instance_reg, OffsetInBytes()));
-          break;
-        case kFloat64x2Cid:
-          __ Comment("UnboxedFloat64x2LoadFieldInstr");
-          __ movups(result,
-                    compiler::FieldAddress(instance_reg, OffsetInBytes()));
-          break;
-        default:
-          UNREACHABLE();
-      }
-      return;
-    }
-
     Register temp = locs()->temp(0).reg();
     __ movq(temp, compiler::FieldAddress(instance_reg, OffsetInBytes()));
+    intptr_t cid = slot().field().UnboxedFieldCid();
     switch (cid) {
       case kDoubleCid:
         __ Comment("UnboxedDoubleLoadFieldInstr");
@@ -2945,7 +2890,7 @@ void InitInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
   compiler::Label no_call;
 
-  __ movq(temp, compiler::FieldAddress(instance, field().TargetOffset()));
+  __ movq(temp, compiler::FieldAddress(instance, field().Offset()));
   __ CompareObject(temp, Object::sentinel());
   __ j(NOT_EQUAL, &no_call, compiler::Assembler::kNearJump);
 
diff --git a/runtime/vm/compiler/frontend/bytecode_flow_graph_builder.cc b/runtime/vm/compiler/frontend/bytecode_flow_graph_builder.cc
index 58641e6fcb3c8..42006a55ee507 100644
--- a/runtime/vm/compiler/frontend/bytecode_flow_graph_builder.cc
+++ b/runtime/vm/compiler/frontend/bytecode_flow_graph_builder.cc
@@ -1151,7 +1151,7 @@ void BytecodeFlowGraphBuilder::BuildCreateArrayTOS() {
 }
 
 const Slot& ClosureSlotByField(const Field& field) {
-  const intptr_t offset = field.HostOffset();
+  const intptr_t offset = field.Offset();
   if (offset == Closure::instantiator_type_arguments_offset()) {
     return Slot::Closure_instantiator_type_arguments();
   } else if (offset == Closure::function_type_arguments_offset()) {
@@ -1178,7 +1178,7 @@ void BytecodeFlowGraphBuilder::BuildStoreFieldTOS() {
 
   const Field& field = Field::Cast(ConstantAt(cp_index, 1).value());
   ASSERT(Smi::Cast(ConstantAt(cp_index).value()).Value() * kWordSize ==
-         field.HostOffset());
+         field.Offset());
 
   if (field.Owner() == isolate()->object_store()->closure_class()) {
     // Stores to _Closure fields are lower-level.
@@ -1204,7 +1204,7 @@ void BytecodeFlowGraphBuilder::BuildLoadFieldTOS() {
 
   const Field& field = Field::Cast(ConstantAt(cp_index, 1).value());
   ASSERT(Smi::Cast(ConstantAt(cp_index).value()).Value() * kWordSize ==
-         field.HostOffset());
+         field.Offset());
 
   if (field.Owner() == isolate()->object_store()->closure_class()) {
     // Loads from _Closure fields are lower-level.
@@ -1292,7 +1292,7 @@ void BytecodeFlowGraphBuilder::BuildInitLateField() {
 
   const Field& field = Field::Cast(ConstantAt(cp_index, 1).value());
   ASSERT(Smi::Cast(ConstantAt(cp_index).value()).Value() * kWordSize ==
-         field.HostOffset());
+         field.Offset());
 
   code_ += B->Constant(Object::sentinel());
   code_ += B->StoreInstanceField(
diff --git a/runtime/vm/compiler/frontend/bytecode_reader.cc b/runtime/vm/compiler/frontend/bytecode_reader.cc
index 616e9f3ac3240..f14cd8b112ce5 100644
--- a/runtime/vm/compiler/frontend/bytecode_reader.cc
+++ b/runtime/vm/compiler/frontend/bytecode_reader.cc
@@ -748,7 +748,7 @@ intptr_t BytecodeReaderHelper::ReadConstantPool(const Function& function,
         field ^= ReadObject();
         // InstanceField constant occupies 2 entries.
         // The first entry is used for field offset.
-        obj = Smi::New(field.HostOffset() / kWordSize);
+        obj = Smi::New(field.Offset() / kWordSize);
         pool.SetTypeAt(i, ObjectPool::EntryType::kTaggedObject,
                        ObjectPool::Patchability::kNotPatchable);
         pool.SetObjectAt(i, obj);
@@ -763,7 +763,7 @@ intptr_t BytecodeReaderHelper::ReadConstantPool(const Function& function,
         break;
       case ConstantPoolTag::kTypeArgumentsField:
         cls ^= ReadObject();
-        obj = Smi::New(cls.host_type_arguments_field_offset() / kWordSize);
+        obj = Smi::New(cls.type_arguments_field_offset() / kWordSize);
         break;
       case ConstantPoolTag::kType:
         obj = ReadObject();
diff --git a/runtime/vm/compiler/runtime_api.cc b/runtime/vm/compiler/runtime_api.cc
index d24699f8ccf14..d628ac8454123 100644
--- a/runtime/vm/compiler/runtime_api.cc
+++ b/runtime/vm/compiler/runtime_api.cc
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/compiler/runtime_api.h"
+#include "platform/utils.h"
 
 namespace dart {
 namespace compiler {
@@ -198,7 +199,7 @@ const Field& LookupMathRandomStateFieldOffset() {
 }
 
 word LookupFieldOffsetInBytes(const Field& field) {
-  return field.TargetOffset();
+  return field.Offset();
 }
 
 #if defined(TARGET_ARCH_IA32)
@@ -336,10 +337,10 @@ static uword GetInstanceSizeImpl(const dart::Class& handle) {
   case kExternalTypedData##clazz##Cid:
       CLASS_LIST_TYPED_DATA(HANDLE_CASE)
 #undef HANDLE_CASE
-      return handle.target_instance_size();
+      return TranslateOffsetInWords(handle.instance_size());
     default:
       if (handle.id() >= kNumPredefinedCids) {
-        return handle.target_instance_size();
+        return TranslateOffsetInWords(handle.instance_size());
       }
   }
   FATAL3("Unsupported class for size translation: %s (id=%" Pd
@@ -358,12 +359,11 @@ intptr_t Class::NumTypeArguments(const dart::Class& klass) {
 }
 
 bool Class::HasTypeArgumentsField(const dart::Class& klass) {
-  return klass.host_type_arguments_field_offset() !=
-         dart::Class::kNoTypeArguments;
+  return klass.type_arguments_field_offset() != dart::Class::kNoTypeArguments;
 }
 
 intptr_t Class::TypeArgumentsFieldOffset(const dart::Class& klass) {
-  return klass.target_type_arguments_field_offset();
+  return TranslateOffsetInWords(klass.type_arguments_field_offset());
 }
 
 bool Class::TraceAllocation(const dart::Class& klass) {
@@ -643,7 +643,7 @@ bool Heap::IsAllocatableInNewSpace(intptr_t instance_size) {
 }
 
 word Field::OffsetOf(const dart::Field& field) {
-  return field.TargetOffset();
+  return TranslateOffsetInWords(field.Offset());
 }
 
 word FieldTable::OffsetOf(const dart::Field& field) {
@@ -651,314 +651,6 @@ word FieldTable::OffsetOf(const dart::Field& field) {
       dart::FieldTable::FieldOffsetFor(field.field_id()));
 }
 
-word FreeListElement::FakeInstance::InstanceSize() {
-  return 0;
-}
-
-word ForwardingCorpse::FakeInstance::InstanceSize() {
-  return 0;
-}
-
-word Instance::NextFieldOffset() {
-  return TranslateOffsetInWords(dart::Instance::NextFieldOffset());
-}
-
-word Pointer::NextFieldOffset() {
-  return TranslateOffsetInWords(dart::Pointer::NextFieldOffset());
-}
-
-word ObjectPool::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Class::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Function::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ICData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word MegamorphicCache::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word SingleTargetCache::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Array::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word GrowableObjectArray::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TypedDataBase::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TypedData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ExternalTypedData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TypedDataView::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word LinkedHashMap::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Type::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TypeRef::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Double::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Mint::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word String::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word OneByteString::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TwoByteString::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ExternalOneByteString::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ExternalTwoByteString::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Int32x4::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Float32x4::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Float64x2::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word DynamicLibrary::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word PatchClass::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word SignatureData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word RedirectionData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word FfiTrampolineData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Script::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Library::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Namespace::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word KernelProgramInfo::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Bytecode::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word PcDescriptors::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word CodeSourceMap::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word CompressedStackMaps::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word LocalVarDescriptors::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ExceptionHandlers::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ContextScope::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ParameterTypeCheck::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word UnlinkedCall::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ApiError::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word LanguageError::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word UnhandledException::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word UnwindError::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Bool::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TypeParameter::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word LibraryPrefix::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Capability::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ReceivePort::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word SendPort::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TransferableTypedData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word StackTrace::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Integer::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Smi::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word WeakProperty::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word MirrorReference::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Number::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word MonomorphicSmiableCall::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Instructions::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Code::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word SubtypeTestCache::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Context::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Closure::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ClosureData::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word RegExp::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word UserTag::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word Field::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word TypeArguments::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word FreeListElement::FakeInstance::NextFieldOffset() {
-  return -kWordSize;
-}
-
-word ForwardingCorpse::FakeInstance::NextFieldOffset() {
-  return -kWordSize;
-}
-
 }  // namespace target
 }  // namespace compiler
 }  // namespace dart
diff --git a/runtime/vm/compiler/runtime_api.h b/runtime/vm/compiler/runtime_api.h
index 4c14afde1eaa0..c7d5b96329de8 100644
--- a/runtime/vm/compiler/runtime_api.h
+++ b/runtime/vm/compiler/runtime_api.h
@@ -19,7 +19,6 @@
 // in compiler::target namespace.
 
 #include "platform/globals.h"
-#include "platform/utils.h"
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
 #include "vm/bss_relocs.h"
@@ -286,11 +285,6 @@ extern const word kPageSize;
 extern const word kPageSizeInWords;
 extern const word kPageMask;
 
-static constexpr intptr_t kObjectAlignment = ObjectAlignment::kObjectAlignment;
-
-inline intptr_t RoundedAllocationSize(intptr_t size) {
-  return Utils::RoundUp(size, kObjectAlignment);
-}
 // Information about frame_layout that compiler should be targeting.
 extern FrameLayout frame_layout;
 
@@ -382,15 +376,11 @@ class ObjectPool : public AllStatic {
  public:
   // Return offset to the element with the given [index] in the object pool.
   static word element_offset(intptr_t index);
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Class : public AllStatic {
  public:
-  static word host_type_arguments_field_offset_in_words_offset();
-
-  static word target_type_arguments_field_offset_in_words_offset();
+  static word type_arguments_field_offset_in_words_offset();
 
   static word declaration_type_offset();
 
@@ -402,10 +392,6 @@ class Class : public AllStatic {
   // The value used if no type arguments vector is present.
   static const word kNoTypeArguments;
 
-  static word InstanceSize();
-
-  static word NextFieldOffset();
-
   // Return class id of the given class on the target.
   static classid_t GetId(const dart::Class& handle);
 
@@ -432,7 +418,6 @@ class Instance : public AllStatic {
   static word DataOffsetFor(intptr_t cid);
   static word ElementSizeFor(intptr_t cid);
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Function : public AllStatic {
@@ -440,8 +425,6 @@ class Function : public AllStatic {
   static word code_offset();
   static word entry_point_offset(CodeEntryKind kind = CodeEntryKind::kNormal);
   static word usage_counter_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class ICData : public AllStatic {
@@ -460,8 +443,6 @@ class ICData : public AllStatic {
   static word EntryPointIndexFor(word num_args);
   static word NumArgsTestedShift();
   static word NumArgsTestedMask();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class MegamorphicCache : public AllStatic {
@@ -470,8 +451,6 @@ class MegamorphicCache : public AllStatic {
   static word mask_offset();
   static word buckets_offset();
   static word arguments_descriptor_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class SingleTargetCache : public AllStatic {
@@ -480,8 +459,6 @@ class SingleTargetCache : public AllStatic {
   static word upper_limit_offset();
   static word entry_point_offset();
   static word target_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Array : public AllStatic {
@@ -492,8 +469,6 @@ class Array : public AllStatic {
   static word type_arguments_offset();
   static word length_offset();
   static word element_offset(intptr_t index);
-  static word InstanceSize();
-  static word NextFieldOffset();
 
   static const word kMaxElements;
   static const word kMaxNewSpaceElements;
@@ -505,7 +480,6 @@ class GrowableObjectArray : public AllStatic {
   static word type_arguments_offset();
   static word length_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class TypedDataBase : public AllStatic {
@@ -513,29 +487,23 @@ class TypedDataBase : public AllStatic {
   static word data_field_offset();
   static word length_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class TypedData : public AllStatic {
  public:
   static word data_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class ExternalTypedData : public AllStatic {
  public:
   static word data_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class TypedDataView : public AllStatic {
  public:
   static word offset_in_bytes_offset();
   static word data_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class LinkedHashMap : public AllStatic {
@@ -545,9 +513,7 @@ class LinkedHashMap : public AllStatic {
   static word hash_mask_offset();
   static word used_data_offset();
   static word deleted_keys_offset();
-  static word type_arguments_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class ArgumentsDescriptor : public AllStatic {
@@ -564,9 +530,6 @@ class ArgumentsDescriptor : public AllStatic {
 class Pointer : public AllStatic {
  public:
   static word c_memory_address_offset();
-  static word type_arguments_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class AbstractType : public AllStatic {
@@ -582,15 +545,11 @@ class Type : public AllStatic {
   static word signature_offset();
   static word type_class_id_offset();
   static word nullability_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class TypeRef : public AllStatic {
  public:
   static word type_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Nullability : public AllStatic {
@@ -605,14 +564,12 @@ class Double : public AllStatic {
  public:
   static word value_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Mint : public AllStatic {
  public:
   static word value_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class String : public AllStatic {
@@ -622,265 +579,43 @@ class String : public AllStatic {
   static word hash_offset();
   static word length_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class OneByteString : public AllStatic {
  public:
   static word data_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class TwoByteString : public AllStatic {
  public:
   static word data_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class ExternalOneByteString : public AllStatic {
  public:
   static word external_data_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class ExternalTwoByteString : public AllStatic {
  public:
   static word external_data_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Int32x4 : public AllStatic {
  public:
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Float32x4 : public AllStatic {
  public:
   static word value_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Float64x2 : public AllStatic {
  public:
   static word value_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class DynamicLibrary : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class PatchClass : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class SignatureData : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class RedirectionData : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class FfiTrampolineData : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Script : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Library : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Namespace : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class KernelProgramInfo : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Bytecode : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class PcDescriptors : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class CodeSourceMap : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class CompressedStackMaps : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class LocalVarDescriptors : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class ExceptionHandlers : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class ContextScope : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class ParameterTypeCheck : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class UnlinkedCall : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class ApiError : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class LanguageError : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class UnhandledException : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class UnwindError : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Bool : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class TypeParameter : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class LibraryPrefix : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Capability : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class ReceivePort : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class SendPort : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class TransferableTypedData : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class StackTrace : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Integer : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Smi : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class WeakProperty : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class MirrorReference : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class Number : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class TimelineStream : public AllStatic {
@@ -898,8 +633,6 @@ class MonomorphicSmiableCall : public AllStatic {
   static word expected_cid_offset();
   static word entrypoint_offset();
   static word target_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Thread : public AllStatic {
@@ -1070,8 +803,6 @@ class Instructions : public AllStatic {
   static const word kPolymorphicEntryOffsetAOT;
   static word HeaderSize();
   static word UnalignedHeaderSize();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Code : public AllStatic {
@@ -1084,8 +815,6 @@ class Code : public AllStatic {
   static word entry_point_offset(CodeEntryKind kind = CodeEntryKind::kNormal);
   static word saved_instructions_offset();
   static word owner_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class SubtypeTestCache : public AllStatic {
@@ -1100,8 +829,6 @@ class SubtypeTestCache : public AllStatic {
   static const word kInstanceParentFunctionTypeArguments;
   static const word kInstanceDelayedFunctionTypeArguments;
   static const word kTestResult;
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Context : public AllStatic {
@@ -1111,8 +838,6 @@ class Context : public AllStatic {
   static word num_variables_offset();
   static word variable_offset(word i);
   static word InstanceSize(word n);
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Closure : public AllStatic {
@@ -1124,13 +849,6 @@ class Closure : public AllStatic {
   static word instantiator_type_arguments_offset();
   static word hash_offset();
   static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class ClosureData : public AllStatic {
- public:
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class HeapPage : public AllStatic {
@@ -1165,15 +883,11 @@ class NativeEntry {
 class RegExp : public AllStatic {
  public:
   static word function_offset(classid_t cid, bool sticky);
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class UserTag : public AllStatic {
  public:
   static word tag_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class Symbols : public AllStatic {
@@ -1192,34 +906,12 @@ class Field : public AllStatic {
   static word is_nullable_offset();
   static word static_value_offset();
   static word kind_bits_offset();
-  static word InstanceSize();
-  static word NextFieldOffset();
 };
 
 class TypeArguments : public AllStatic {
  public:
   static word instantiations_offset();
   static word type_at_offset(intptr_t i);
-  static word InstanceSize();
-  static word NextFieldOffset();
-};
-
-class FreeListElement : public AllStatic {
- public:
-  class FakeInstance : public AllStatic {
-   public:
-    static word InstanceSize();
-    static word NextFieldOffset();
-  };
-};
-
-class ForwardingCorpse : public AllStatic {
- public:
-  class FakeInstance : public AllStatic {
-   public:
-    static word InstanceSize();
-    static word NextFieldOffset();
-  };
 };
 
 class FieldTable : public AllStatic {
diff --git a/runtime/vm/compiler/runtime_offsets_extracted.h b/runtime/vm/compiler/runtime_offsets_extracted.h
index 1a72097f1a5b4..56174579e9a9c 100644
--- a/runtime/vm/compiler/runtime_offsets_extracted.h
+++ b/runtime/vm/compiler/runtime_offsets_extracted.h
@@ -74,10 +74,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     56;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    90;
+    102;
 static constexpr dart::compiler::target::word Class_super_type_offset = 44;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 104;
+    Class_type_arguments_field_offset_in_words_offset = 92;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 16;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 8;
@@ -111,7 +111,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     24;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 46;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 54;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 60;
 static constexpr dart::compiler::target::word Function_code_offset = 44;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     4, 8};
@@ -146,8 +146,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     12;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 8;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     20;
 static constexpr dart::compiler::target::word
@@ -173,7 +171,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     8;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 8;
 static constexpr dart::compiler::target::word
@@ -392,81 +389,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 28;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     16;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 4;
-static constexpr dart::compiler::target::word Class_InstanceSize = 128;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 16;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 20;
-static constexpr dart::compiler::target::word Context_InstanceSize = 12;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 24;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 20;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 12;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 12;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 16;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Script_InstanceSize = 56;
-static constexpr dart::compiler::target::word Library_InstanceSize = 76;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 20;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    64;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 48;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 8;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 8;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 12;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 8;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 28;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 12;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 40;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 20;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 12;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 4;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 20;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 4;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 4;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 8;
-static constexpr dart::compiler::target::word Number_InstanceSize = 4;
-static constexpr dart::compiler::target::word Function_InstanceSize = 88;
-static constexpr dart::compiler::target::word Field_InstanceSize = 64;
-static constexpr dart::compiler::target::word Code_InstanceSize = 96;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 8;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 8;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 32;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize = 8;
-static constexpr dart::compiler::target::word Array_InstanceSize = 12;
-static constexpr dart::compiler::target::word Type_InstanceSize = 36;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 16;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 60;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 12;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 28;
 #endif  // defined(TARGET_ARCH_ARM)
 
@@ -529,10 +451,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     112;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    170;
+    182;
 static constexpr dart::compiler::target::word Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 184;
+    Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 16;
@@ -566,7 +488,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     48;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 104;
 static constexpr dart::compiler::target::word Function_code_offset = 88;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     8, 16};
@@ -601,8 +523,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     24;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     40;
 static constexpr dart::compiler::target::word
@@ -628,7 +548,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     16;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -849,82 +768,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     32;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word Class_InstanceSize = 208;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 32;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 24;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 32;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word Library_InstanceSize = 144;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    128;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 88;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 16;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 72;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
-static constexpr dart::compiler::target::word Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word Function_InstanceSize = 144;
-static constexpr dart::compiler::target::word Field_InstanceSize = 112;
-static constexpr dart::compiler::target::word Code_InstanceSize = 176;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 12;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
 #endif  // defined(TARGET_ARCH_X64)
 
@@ -985,10 +828,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     56;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    90;
+    102;
 static constexpr dart::compiler::target::word Class_super_type_offset = 44;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 104;
+    Class_type_arguments_field_offset_in_words_offset = 92;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 16;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 8;
@@ -1022,7 +865,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     24;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 46;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 54;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 60;
 static constexpr dart::compiler::target::word Function_code_offset = 44;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     4, 8};
@@ -1057,8 +900,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     12;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 8;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     20;
 static constexpr dart::compiler::target::word
@@ -1084,7 +925,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     8;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 8;
 static constexpr dart::compiler::target::word
@@ -1299,81 +1139,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 28;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     16;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 4;
-static constexpr dart::compiler::target::word Class_InstanceSize = 128;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 16;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 20;
-static constexpr dart::compiler::target::word Context_InstanceSize = 12;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 24;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 20;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 12;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 12;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 16;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Script_InstanceSize = 56;
-static constexpr dart::compiler::target::word Library_InstanceSize = 76;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 20;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    64;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 48;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 8;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 8;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 12;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 8;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 28;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 12;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 40;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 20;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 12;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 4;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 20;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 4;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 4;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 8;
-static constexpr dart::compiler::target::word Number_InstanceSize = 4;
-static constexpr dart::compiler::target::word Function_InstanceSize = 88;
-static constexpr dart::compiler::target::word Field_InstanceSize = 64;
-static constexpr dart::compiler::target::word Code_InstanceSize = 96;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 8;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 8;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 32;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize = 8;
-static constexpr dart::compiler::target::word Array_InstanceSize = 12;
-static constexpr dart::compiler::target::word Type_InstanceSize = 36;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 16;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 60;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 12;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 28;
 #endif  // defined(TARGET_ARCH_IA32)
 
@@ -1436,10 +1201,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     112;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    170;
+    182;
 static constexpr dart::compiler::target::word Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 184;
+    Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 16;
@@ -1473,7 +1238,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     48;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 104;
 static constexpr dart::compiler::target::word Function_code_offset = 88;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     8, 16};
@@ -1508,8 +1273,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     24;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     40;
 static constexpr dart::compiler::target::word
@@ -1535,7 +1298,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     16;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -1757,82 +1519,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     32;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word Class_InstanceSize = 208;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 32;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 24;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 32;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word Library_InstanceSize = 144;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    128;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 88;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 16;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 72;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
-static constexpr dart::compiler::target::word Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word Function_InstanceSize = 144;
-static constexpr dart::compiler::target::word Field_InstanceSize = 112;
-static constexpr dart::compiler::target::word Code_InstanceSize = 176;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 12;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
 #endif  // defined(TARGET_ARCH_ARM64)
 
@@ -1895,10 +1581,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     56;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    90;
+    102;
 static constexpr dart::compiler::target::word Class_super_type_offset = 44;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 104;
+    Class_type_arguments_field_offset_in_words_offset = 92;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 16;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 8;
@@ -1930,7 +1616,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     24;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 46;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 54;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 60;
 static constexpr dart::compiler::target::word Function_code_offset = 44;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     4, 8};
@@ -1964,8 +1650,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     12;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 8;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     20;
 static constexpr dart::compiler::target::word
@@ -1991,7 +1675,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     8;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 8;
 static constexpr dart::compiler::target::word
@@ -2207,81 +1890,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 28;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     16;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 4;
-static constexpr dart::compiler::target::word Class_InstanceSize = 128;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 16;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 20;
-static constexpr dart::compiler::target::word Context_InstanceSize = 12;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 24;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 20;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 12;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 12;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 16;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Script_InstanceSize = 56;
-static constexpr dart::compiler::target::word Library_InstanceSize = 76;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 20;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    64;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 44;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 8;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 8;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 12;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 8;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 28;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 12;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 40;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 20;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 12;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 4;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 20;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 4;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 4;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 8;
-static constexpr dart::compiler::target::word Number_InstanceSize = 4;
-static constexpr dart::compiler::target::word Function_InstanceSize = 88;
-static constexpr dart::compiler::target::word Field_InstanceSize = 64;
-static constexpr dart::compiler::target::word Code_InstanceSize = 76;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 8;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 8;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 32;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize = 8;
-static constexpr dart::compiler::target::word Array_InstanceSize = 12;
-static constexpr dart::compiler::target::word Type_InstanceSize = 36;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 16;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 60;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 12;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 28;
 #endif  // defined(TARGET_ARCH_ARM)
 
@@ -2344,10 +1952,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     112;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    170;
+    182;
 static constexpr dart::compiler::target::word Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 184;
+    Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 16;
@@ -2379,7 +1987,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     48;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 104;
 static constexpr dart::compiler::target::word Function_code_offset = 88;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     8, 16};
@@ -2413,8 +2021,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     24;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     40;
 static constexpr dart::compiler::target::word
@@ -2440,7 +2046,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     16;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -2658,82 +2263,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     32;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word Class_InstanceSize = 208;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 32;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 24;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 32;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word Library_InstanceSize = 144;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    128;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 80;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 16;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 72;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
-static constexpr dart::compiler::target::word Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word Function_InstanceSize = 144;
-static constexpr dart::compiler::target::word Field_InstanceSize = 112;
-static constexpr dart::compiler::target::word Code_InstanceSize = 144;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 12;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
 #endif  // defined(TARGET_ARCH_X64)
 
@@ -2794,10 +2323,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     56;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    90;
+    102;
 static constexpr dart::compiler::target::word Class_super_type_offset = 44;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 104;
+    Class_type_arguments_field_offset_in_words_offset = 92;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 16;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 8;
@@ -2829,7 +2358,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     24;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 46;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 54;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 60;
 static constexpr dart::compiler::target::word Function_code_offset = 44;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     4, 8};
@@ -2863,8 +2392,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     12;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 8;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     20;
 static constexpr dart::compiler::target::word
@@ -2890,7 +2417,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     8;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 8;
 static constexpr dart::compiler::target::word
@@ -3102,81 +2628,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 28;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     16;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 4;
-static constexpr dart::compiler::target::word Class_InstanceSize = 128;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 16;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 20;
-static constexpr dart::compiler::target::word Context_InstanceSize = 12;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 24;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 20;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 12;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 12;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 16;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Script_InstanceSize = 56;
-static constexpr dart::compiler::target::word Library_InstanceSize = 76;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 20;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    64;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 44;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 8;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 8;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 12;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 8;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 28;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 12;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 8;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 40;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 20;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 12;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 4;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 20;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 4;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 4;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 8;
-static constexpr dart::compiler::target::word Number_InstanceSize = 4;
-static constexpr dart::compiler::target::word Function_InstanceSize = 88;
-static constexpr dart::compiler::target::word Field_InstanceSize = 64;
-static constexpr dart::compiler::target::word Code_InstanceSize = 76;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 8;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 8;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 32;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize = 8;
-static constexpr dart::compiler::target::word Array_InstanceSize = 12;
-static constexpr dart::compiler::target::word Type_InstanceSize = 36;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 16;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 60;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 12;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 28;
 #endif  // defined(TARGET_ARCH_IA32)
 
@@ -3239,10 +2690,10 @@ static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word Class_declaration_type_offset =
     112;
 static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
-    170;
+    182;
 static constexpr dart::compiler::target::word Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    Class_host_type_arguments_field_offset_in_words_offset = 184;
+    Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word ClassTable_table_offset = 16;
@@ -3274,7 +2725,7 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
     48;
 static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
-static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 104;
 static constexpr dart::compiler::target::word Function_code_offset = 88;
 static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
     8, 16};
@@ -3308,8 +2759,6 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
     24;
 static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
-static constexpr dart::compiler::target::word
-    LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
     40;
 static constexpr dart::compiler::target::word
@@ -3335,7 +2784,6 @@ static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
 static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
 static constexpr dart::compiler::target::word Pointer_c_memory_address_offset =
     16;
-static constexpr dart::compiler::target::word Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -3554,82 +3002,6 @@ static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
     32;
 static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word Class_InstanceSize = 208;
-static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
-static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 32;
-static constexpr dart::compiler::target::word ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
-static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
-static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word SignatureData_InstanceSize = 24;
-static constexpr dart::compiler::target::word RedirectionData_InstanceSize = 32;
-static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word Library_InstanceSize = 144;
-static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
-    128;
-static constexpr dart::compiler::target::word Bytecode_InstanceSize = 80;
-static constexpr dart::compiler::target::word PcDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word CodeSourceMap_InstanceSize = 16;
-static constexpr dart::compiler::target::word CompressedStackMaps_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
-static constexpr dart::compiler::target::word ParameterTypeCheck_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
-static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 72;
-static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
-static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
-static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
-static constexpr dart::compiler::target::word Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word Function_InstanceSize = 144;
-static constexpr dart::compiler::target::word Field_InstanceSize = 112;
-static constexpr dart::compiler::target::word Code_InstanceSize = 144;
-static constexpr dart::compiler::target::word Instructions_InstanceSize = 12;
-static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
-static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
 #endif  // defined(TARGET_ARCH_ARM64)
 
@@ -3699,10 +3071,10 @@ static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
 static constexpr dart::compiler::target::word
     AOT_Class_declaration_type_offset = 56;
 static constexpr dart::compiler::target::word
-    AOT_Class_num_type_arguments_offset = 90;
+    AOT_Class_num_type_arguments_offset = 102;
 static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 44;
 static constexpr dart::compiler::target::word
-    AOT_Class_host_type_arguments_field_offset_in_words_offset = 104;
+    AOT_Class_type_arguments_field_offset_in_words_offset = 92;
 static constexpr dart::compiler::target::word
     AOT_ClassTable_shared_class_table_offset = 16;
 static constexpr dart::compiler::target::word AOT_ClassTable_table_offset = 8;
@@ -3768,8 +3140,6 @@ static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_hash_mask_offset = 12;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
     8;
-static constexpr dart::compiler::target::word
-    AOT_LinkedHashMap_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_used_data_offset = 20;
 static constexpr dart::compiler::target::word
@@ -3801,8 +3171,6 @@ static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
     12;
 static constexpr dart::compiler::target::word
     AOT_Pointer_c_memory_address_offset = 8;
-static constexpr dart::compiler::target::word
-    AOT_Pointer_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     AOT_SingleTargetCache_entry_point_offset = 8;
 static constexpr dart::compiler::target::word
@@ -4039,98 +3407,6 @@ static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 28;
 static constexpr dart::compiler::target::word
     AOT_GrowableObjectArray_InstanceSize = 16;
 static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 112;
-static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word
-    AOT_ExternalOneByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTwoByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
-    20;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTypedData_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_SignatureData_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_RedirectionData_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_FfiTrampolineData_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 56;
-static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 72;
-static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    AOT_KernelProgramInfo_InstanceSize = 64;
-static constexpr dart::compiler::target::word AOT_Bytecode_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_PcDescriptors_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word AOT_CodeSourceMap_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word
-    AOT_CompressedStackMaps_InstanceSize = 8;
-static constexpr dart::compiler::target::word
-    AOT_LocalVarDescriptors_InstanceSize = 8;
-static constexpr dart::compiler::target::word
-    AOT_ExceptionHandlers_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word
-    AOT_ParameterTypeCheck_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
-    28;
-static constexpr dart::compiler::target::word
-    AOT_UnhandledException_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
-    20;
-static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_TransferableTypedData_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 56;
-static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 80;
-static constexpr dart::compiler::target::word AOT_Instructions_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 8;
-static constexpr dart::compiler::target::word
-    AOT_SingleTargetCache_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_MonomorphicSmiableCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_MegamorphicCache_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_SubtypeTestCache_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 36;
-static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 60;
-static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 12;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
     28;
 #endif  // defined(TARGET_ARCH_ARM)
@@ -4197,10 +3473,10 @@ static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
 static constexpr dart::compiler::target::word
     AOT_Class_declaration_type_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Class_num_type_arguments_offset = 170;
+    AOT_Class_num_type_arguments_offset = 182;
 static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    AOT_Class_host_type_arguments_field_offset_in_words_offset = 184;
+    AOT_Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     AOT_ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word AOT_ClassTable_table_offset = 16;
@@ -4266,8 +3542,6 @@ static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_hash_mask_offset = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
     16;
-static constexpr dart::compiler::target::word
-    AOT_LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_used_data_offset = 40;
 static constexpr dart::compiler::target::word
@@ -4299,8 +3573,6 @@ static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
     16;
 static constexpr dart::compiler::target::word
     AOT_Pointer_c_memory_address_offset = 16;
-static constexpr dart::compiler::target::word
-    AOT_Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -4538,99 +3810,6 @@ static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word
     AOT_GrowableObjectArray_InstanceSize = 32;
 static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 192;
-static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTypedData_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SignatureData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word AOT_RedirectionData_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    AOT_FfiTrampolineData_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 136;
-static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word
-    AOT_KernelProgramInfo_InstanceSize = 128;
-static constexpr dart::compiler::target::word AOT_Bytecode_InstanceSize = 88;
-static constexpr dart::compiler::target::word AOT_PcDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_CodeSourceMap_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_CompressedStackMaps_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    AOT_LocalVarDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_ExceptionHandlers_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ParameterTypeCheck_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word
-    AOT_UnhandledException_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
-    72;
-static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 104;
-static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
-static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 152;
-static constexpr dart::compiler::target::word AOT_Instructions_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_SingleTargetCache_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_MegamorphicCache_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_SubtypeTestCache_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
     56;
 #endif  // defined(TARGET_ARCH_X64)
@@ -4700,10 +3879,10 @@ static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
 static constexpr dart::compiler::target::word
     AOT_Class_declaration_type_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Class_num_type_arguments_offset = 170;
+    AOT_Class_num_type_arguments_offset = 182;
 static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    AOT_Class_host_type_arguments_field_offset_in_words_offset = 184;
+    AOT_Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     AOT_ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word AOT_ClassTable_table_offset = 16;
@@ -4769,8 +3948,6 @@ static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_hash_mask_offset = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
     16;
-static constexpr dart::compiler::target::word
-    AOT_LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_used_data_offset = 40;
 static constexpr dart::compiler::target::word
@@ -4802,8 +3979,6 @@ static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
     16;
 static constexpr dart::compiler::target::word
     AOT_Pointer_c_memory_address_offset = 16;
-static constexpr dart::compiler::target::word
-    AOT_Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -5042,99 +4217,6 @@ static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word
     AOT_GrowableObjectArray_InstanceSize = 32;
 static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 192;
-static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTypedData_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SignatureData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word AOT_RedirectionData_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    AOT_FfiTrampolineData_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 136;
-static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word
-    AOT_KernelProgramInfo_InstanceSize = 128;
-static constexpr dart::compiler::target::word AOT_Bytecode_InstanceSize = 88;
-static constexpr dart::compiler::target::word AOT_PcDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_CodeSourceMap_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_CompressedStackMaps_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    AOT_LocalVarDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_ExceptionHandlers_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ParameterTypeCheck_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word
-    AOT_UnhandledException_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
-    72;
-static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 104;
-static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
-static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 152;
-static constexpr dart::compiler::target::word AOT_Instructions_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_SingleTargetCache_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_MegamorphicCache_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_SubtypeTestCache_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
     56;
 #endif  // defined(TARGET_ARCH_ARM64)
@@ -5203,10 +4285,10 @@ static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
 static constexpr dart::compiler::target::word
     AOT_Class_declaration_type_offset = 56;
 static constexpr dart::compiler::target::word
-    AOT_Class_num_type_arguments_offset = 90;
+    AOT_Class_num_type_arguments_offset = 102;
 static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 44;
 static constexpr dart::compiler::target::word
-    AOT_Class_host_type_arguments_field_offset_in_words_offset = 104;
+    AOT_Class_type_arguments_field_offset_in_words_offset = 92;
 static constexpr dart::compiler::target::word
     AOT_ClassTable_shared_class_table_offset = 16;
 static constexpr dart::compiler::target::word AOT_ClassTable_table_offset = 8;
@@ -5268,8 +4350,6 @@ static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_hash_mask_offset = 12;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
     8;
-static constexpr dart::compiler::target::word
-    AOT_LinkedHashMap_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_used_data_offset = 20;
 static constexpr dart::compiler::target::word
@@ -5301,8 +4381,6 @@ static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
     12;
 static constexpr dart::compiler::target::word
     AOT_Pointer_c_memory_address_offset = 8;
-static constexpr dart::compiler::target::word
-    AOT_Pointer_type_arguments_offset = 4;
 static constexpr dart::compiler::target::word
     AOT_SingleTargetCache_entry_point_offset = 8;
 static constexpr dart::compiler::target::word
@@ -5536,98 +4614,6 @@ static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 28;
 static constexpr dart::compiler::target::word
     AOT_GrowableObjectArray_InstanceSize = 16;
 static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 112;
-static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word
-    AOT_ExternalOneByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTwoByteString_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
-    20;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTypedData_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_SignatureData_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_RedirectionData_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_FfiTrampolineData_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 56;
-static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 72;
-static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 20;
-static constexpr dart::compiler::target::word
-    AOT_KernelProgramInfo_InstanceSize = 64;
-static constexpr dart::compiler::target::word AOT_Bytecode_InstanceSize = 44;
-static constexpr dart::compiler::target::word AOT_PcDescriptors_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word AOT_CodeSourceMap_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word
-    AOT_CompressedStackMaps_InstanceSize = 8;
-static constexpr dart::compiler::target::word
-    AOT_LocalVarDescriptors_InstanceSize = 8;
-static constexpr dart::compiler::target::word
-    AOT_ExceptionHandlers_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word
-    AOT_ParameterTypeCheck_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
-    28;
-static constexpr dart::compiler::target::word
-    AOT_UnhandledException_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
-    20;
-static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_TransferableTypedData_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 20;
-static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
-    8;
-static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 4;
-static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 56;
-static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 60;
-static constexpr dart::compiler::target::word AOT_Instructions_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 8;
-static constexpr dart::compiler::target::word
-    AOT_SingleTargetCache_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_MonomorphicSmiableCall_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_MegamorphicCache_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_SubtypeTestCache_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 36;
-static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 60;
-static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 12;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
     28;
 #endif  // defined(TARGET_ARCH_ARM)
@@ -5694,10 +4680,10 @@ static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
 static constexpr dart::compiler::target::word
     AOT_Class_declaration_type_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Class_num_type_arguments_offset = 170;
+    AOT_Class_num_type_arguments_offset = 182;
 static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    AOT_Class_host_type_arguments_field_offset_in_words_offset = 184;
+    AOT_Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     AOT_ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word AOT_ClassTable_table_offset = 16;
@@ -5759,8 +4745,6 @@ static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_hash_mask_offset = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
     16;
-static constexpr dart::compiler::target::word
-    AOT_LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_used_data_offset = 40;
 static constexpr dart::compiler::target::word
@@ -5792,8 +4776,6 @@ static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
     16;
 static constexpr dart::compiler::target::word
     AOT_Pointer_c_memory_address_offset = 16;
-static constexpr dart::compiler::target::word
-    AOT_Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -6028,99 +5010,6 @@ static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word
     AOT_GrowableObjectArray_InstanceSize = 32;
 static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 192;
-static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTypedData_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SignatureData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word AOT_RedirectionData_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    AOT_FfiTrampolineData_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 136;
-static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word
-    AOT_KernelProgramInfo_InstanceSize = 128;
-static constexpr dart::compiler::target::word AOT_Bytecode_InstanceSize = 80;
-static constexpr dart::compiler::target::word AOT_PcDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_CodeSourceMap_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_CompressedStackMaps_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    AOT_LocalVarDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_ExceptionHandlers_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ParameterTypeCheck_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word
-    AOT_UnhandledException_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
-    72;
-static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 104;
-static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
-static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 120;
-static constexpr dart::compiler::target::word AOT_Instructions_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_SingleTargetCache_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_MegamorphicCache_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_SubtypeTestCache_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
     56;
 #endif  // defined(TARGET_ARCH_X64)
@@ -6190,10 +5079,10 @@ static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
 static constexpr dart::compiler::target::word
     AOT_Class_declaration_type_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Class_num_type_arguments_offset = 170;
+    AOT_Class_num_type_arguments_offset = 182;
 static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
 static constexpr dart::compiler::target::word
-    AOT_Class_host_type_arguments_field_offset_in_words_offset = 184;
+    AOT_Class_type_arguments_field_offset_in_words_offset = 172;
 static constexpr dart::compiler::target::word
     AOT_ClassTable_shared_class_table_offset = 32;
 static constexpr dart::compiler::target::word AOT_ClassTable_table_offset = 16;
@@ -6255,8 +5144,6 @@ static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_hash_mask_offset = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
     16;
-static constexpr dart::compiler::target::word
-    AOT_LinkedHashMap_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_LinkedHashMap_used_data_offset = 40;
 static constexpr dart::compiler::target::word
@@ -6288,8 +5175,6 @@ static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
     16;
 static constexpr dart::compiler::target::word
     AOT_Pointer_c_memory_address_offset = 16;
-static constexpr dart::compiler::target::word
-    AOT_Pointer_type_arguments_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SingleTargetCache_entry_point_offset = 16;
 static constexpr dart::compiler::target::word
@@ -6525,99 +5410,6 @@ static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
 static constexpr dart::compiler::target::word
     AOT_GrowableObjectArray_InstanceSize = 32;
 static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 192;
-static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ExternalOneByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTwoByteString_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word
-    AOT_ExternalTypedData_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SignatureData_InstanceSize =
-    24;
-static constexpr dart::compiler::target::word AOT_RedirectionData_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word
-    AOT_FfiTrampolineData_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 96;
-static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 136;
-static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
-static constexpr dart::compiler::target::word
-    AOT_KernelProgramInfo_InstanceSize = 128;
-static constexpr dart::compiler::target::word AOT_Bytecode_InstanceSize = 80;
-static constexpr dart::compiler::target::word AOT_PcDescriptors_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_CodeSourceMap_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_CompressedStackMaps_InstanceSize = 12;
-static constexpr dart::compiler::target::word
-    AOT_LocalVarDescriptors_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_ExceptionHandlers_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word
-    AOT_ParameterTypeCheck_InstanceSize = 48;
-static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
-    48;
-static constexpr dart::compiler::target::word
-    AOT_UnhandledException_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 12;
-static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
-    72;
-static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
-    40;
-static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
-static constexpr dart::compiler::target::word
-    AOT_TransferableTypedData_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
-static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
-    32;
-static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
-    16;
-static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
-static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 104;
-static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
-static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 120;
-static constexpr dart::compiler::target::word AOT_Instructions_InstanceSize =
-    12;
-static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
-static constexpr dart::compiler::target::word
-    AOT_SingleTargetCache_InstanceSize = 32;
-static constexpr dart::compiler::target::word
-    AOT_MonomorphicSmiableCall_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_MegamorphicCache_InstanceSize = 48;
-static constexpr dart::compiler::target::word
-    AOT_SubtypeTestCache_InstanceSize = 16;
-static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
-static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 64;
-static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
-static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
-static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
     56;
 #endif  // defined(TARGET_ARCH_ARM64)
diff --git a/runtime/vm/compiler/runtime_offsets_list.h b/runtime/vm/compiler/runtime_offsets_list.h
index 296daf4159b74..3c243bb21f7b3 100644
--- a/runtime/vm/compiler/runtime_offsets_list.h
+++ b/runtime/vm/compiler/runtime_offsets_list.h
@@ -64,7 +64,7 @@
   FIELD(Class, declaration_type_offset)                                        \
   FIELD(Class, num_type_arguments_offset)                                      \
   FIELD(Class, super_type_offset)                                              \
-  FIELD(Class, host_type_arguments_field_offset_in_words_offset)               \
+  FIELD(Class, type_arguments_field_offset_in_words_offset)                    \
   FIELD(ClassTable, shared_class_table_offset)                                 \
   FIELD(ClassTable, table_offset)                                              \
   NOT_IN_PRODUCT(FIELD(SharedClassTable, class_heap_stats_table_offset))       \
@@ -115,7 +115,6 @@
   FIELD(LinkedHashMap, deleted_keys_offset)                                    \
   FIELD(LinkedHashMap, hash_mask_offset)                                       \
   FIELD(LinkedHashMap, index_offset)                                           \
-  FIELD(LinkedHashMap, type_arguments_offset)                                  \
   FIELD(LinkedHashMap, used_data_offset)                                       \
   FIELD(MarkingStackBlock, pointers_offset)                                    \
   FIELD(MarkingStackBlock, top_offset)                                         \
@@ -132,7 +131,6 @@
   FIELD(ObjectStore, string_type_offset)                                       \
   FIELD(OneByteString, data_offset)                                            \
   FIELD(Pointer, c_memory_address_offset)                                      \
-  FIELD(Pointer, type_arguments_offset)                                        \
   FIELD(SingleTargetCache, entry_point_offset)                                 \
   FIELD(SingleTargetCache, lower_limit_offset)                                 \
   FIELD(SingleTargetCache, target_offset)                                      \
@@ -253,84 +251,22 @@
       Thread, write_barrier_wrappers_thread_offset, Register, 0,               \
       kNumberOfCpuRegisters - 1,                                               \
       [](Register reg) { return (kDartAvailableCpuRegs & (1 << reg)) != 0; })) \
-                                                                               \
-  SIZEOF(ApiError, InstanceSize, RawApiError)                                  \
-  SIZEOF(Array, InstanceSize, RawArray)                                        \
   SIZEOF(Array, header_size, RawArray)                                         \
-  SIZEOF(Bool, InstanceSize, RawBool)                                          \
-  SIZEOF(Bytecode, InstanceSize, RawBytecode)                                  \
-  SIZEOF(Capability, InstanceSize, RawCapability)                              \
-  SIZEOF(Class, InstanceSize, RawClass)                                        \
-  SIZEOF(Closure, InstanceSize, RawClosure)                                    \
-  SIZEOF(ClosureData, InstanceSize, RawClosureData)                            \
-  SIZEOF(Code, InstanceSize, RawCode)                                          \
-  SIZEOF(CodeSourceMap, InstanceSize, RawCodeSourceMap)                        \
-  SIZEOF(CompressedStackMaps, InstanceSize, RawCompressedStackMaps)            \
-  SIZEOF(Context, InstanceSize, RawContext)                                    \
   SIZEOF(Context, header_size, RawContext)                                     \
-  SIZEOF(ContextScope, InstanceSize, RawContextScope)                          \
   SIZEOF(Double, InstanceSize, RawDouble)                                      \
-  SIZEOF(DynamicLibrary, InstanceSize, RawDynamicLibrary)                      \
-  SIZEOF(ExceptionHandlers, InstanceSize, RawExceptionHandlers)                \
-  SIZEOF(ExternalOneByteString, InstanceSize, RawExternalOneByteString)        \
-  SIZEOF(ExternalTwoByteString, InstanceSize, RawExternalTwoByteString)        \
-  SIZEOF(ExternalTypedData, InstanceSize, RawExternalTypedData)                \
-  SIZEOF(FfiTrampolineData, InstanceSize, RawFfiTrampolineData)                \
-  SIZEOF(Field, InstanceSize, RawField)                                        \
   SIZEOF(Float32x4, InstanceSize, RawFloat32x4)                                \
   SIZEOF(Float64x2, InstanceSize, RawFloat64x2)                                \
-  SIZEOF(Function, InstanceSize, RawFunction)                                  \
-  SIZEOF(GrowableObjectArray, InstanceSize, RawGrowableObjectArray)            \
-  SIZEOF(ICData, InstanceSize, RawICData)                                      \
-  SIZEOF(Instance, InstanceSize, RawInstance)                                  \
-  SIZEOF(Instructions, InstanceSize, RawInstructions)                          \
   SIZEOF(Instructions, UnalignedHeaderSize, RawInstructions)                   \
   SIZEOF(Int32x4, InstanceSize, RawInt32x4)                                    \
-  SIZEOF(Integer, InstanceSize, RawInteger)                                    \
-  SIZEOF(KernelProgramInfo, InstanceSize, RawKernelProgramInfo)                \
-  SIZEOF(LanguageError, InstanceSize, RawLanguageError)                        \
-  SIZEOF(Library, InstanceSize, RawLibrary)                                    \
-  SIZEOF(LibraryPrefix, InstanceSize, RawLibraryPrefix)                        \
-  SIZEOF(LinkedHashMap, InstanceSize, RawLinkedHashMap)                        \
-  SIZEOF(LocalVarDescriptors, InstanceSize, RawLocalVarDescriptors)            \
-  SIZEOF(MegamorphicCache, InstanceSize, RawMegamorphicCache)                  \
   SIZEOF(Mint, InstanceSize, RawMint)                                          \
-  SIZEOF(MirrorReference, InstanceSize, RawMirrorReference)                    \
-  SIZEOF(MonomorphicSmiableCall, InstanceSize, RawMonomorphicSmiableCall)      \
-  SIZEOF(Namespace, InstanceSize, RawNamespace)                                \
   SIZEOF(NativeArguments, StructSize, NativeArguments)                         \
-  SIZEOF(Number, InstanceSize, RawNumber)                                      \
-  SIZEOF(Object, InstanceSize, RawObject)                                      \
-  SIZEOF(ObjectPool, InstanceSize, RawObjectPool)                              \
-  SIZEOF(OneByteString, InstanceSize, RawOneByteString)                        \
-  SIZEOF(ParameterTypeCheck, InstanceSize, RawParameterTypeCheck)              \
-  SIZEOF(PatchClass, InstanceSize, RawPatchClass)                              \
-  SIZEOF(PcDescriptors, InstanceSize, RawPcDescriptors)                        \
-  SIZEOF(Pointer, InstanceSize, RawPointer)                                    \
-  SIZEOF(ReceivePort, InstanceSize, RawReceivePort)                            \
-  SIZEOF(RedirectionData, InstanceSize, RawRedirectionData)                    \
-  SIZEOF(RegExp, InstanceSize, RawRegExp)                                      \
-  SIZEOF(Script, InstanceSize, RawScript)                                      \
-  SIZEOF(SendPort, InstanceSize, RawSendPort)                                  \
-  SIZEOF(SignatureData, InstanceSize, RawSignatureData)                        \
-  SIZEOF(SingleTargetCache, InstanceSize, RawSingleTargetCache)                \
-  SIZEOF(Smi, InstanceSize, RawSmi)                                            \
-  SIZEOF(StackTrace, InstanceSize, RawStackTrace)                              \
   SIZEOF(String, InstanceSize, RawString)                                      \
-  SIZEOF(SubtypeTestCache, InstanceSize, RawSubtypeTestCache)                  \
-  SIZEOF(TransferableTypedData, InstanceSize, RawTransferableTypedData)        \
-  SIZEOF(TwoByteString, InstanceSize, RawTwoByteString)                        \
-  SIZEOF(Type, InstanceSize, RawType)                                          \
-  SIZEOF(TypeArguments, InstanceSize, RawTypeArguments)                        \
-  SIZEOF(TypeParameter, InstanceSize, RawTypeParameter)                        \
-  SIZEOF(TypeRef, InstanceSize, RawTypeRef)                                    \
   SIZEOF(TypedData, InstanceSize, RawTypedData)                                \
+  SIZEOF(Object, InstanceSize, RawObject)                                      \
   SIZEOF(TypedDataBase, InstanceSize, RawTypedDataBase)                        \
-  SIZEOF(TypedDataView, InstanceSize, RawTypedDataView)                        \
-  SIZEOF(UnhandledException, InstanceSize, RawUnhandledException)              \
-  SIZEOF(UnlinkedCall, InstanceSize, RawUnlinkedCall)                          \
-  SIZEOF(UnwindError, InstanceSize, RawUnwindError)                            \
-  SIZEOF(UserTag, InstanceSize, RawUserTag)                                    \
-  SIZEOF(WeakProperty, InstanceSize, RawWeakProperty)
+  SIZEOF(Closure, InstanceSize, RawClosure)                                    \
+  SIZEOF(GrowableObjectArray, InstanceSize, RawGrowableObjectArray)            \
+  SIZEOF(Instance, InstanceSize, RawInstance)                                  \
+  SIZEOF(LinkedHashMap, InstanceSize, RawLinkedHashMap)
 
 #endif  // RUNTIME_VM_COMPILER_RUNTIME_OFFSETS_LIST_H_
diff --git a/runtime/vm/compiler/stub_code_compiler_arm.cc b/runtime/vm/compiler/stub_code_compiler_arm.cc
index 0fdf071ad1804..b6f3c2b86821e 100644
--- a/runtime/vm/compiler/stub_code_compiler_arm.cc
+++ b/runtime/vm/compiler/stub_code_compiler_arm.cc
@@ -2726,8 +2726,8 @@ static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
       __ mov(kInstanceInstantiatorTypeArgumentsReg, Operand(kNullReg));
       __ ldr(R9,
              FieldAddress(
-                 R9, target::Class::
-                         host_type_arguments_field_offset_in_words_offset()));
+                 R9,
+                 target::Class::type_arguments_field_offset_in_words_offset()));
       __ CompareImmediate(R9, target::Class::kNoTypeArguments);
       __ b(&has_no_type_arguments, EQ);
       __ add(R9, kInstanceReg, Operand(R9, LSL, 2));
diff --git a/runtime/vm/compiler/stub_code_compiler_arm64.cc b/runtime/vm/compiler/stub_code_compiler_arm64.cc
index 34d927a4ac15b..cab25a16fda09 100644
--- a/runtime/vm/compiler/stub_code_compiler_arm64.cc
+++ b/runtime/vm/compiler/stub_code_compiler_arm64.cc
@@ -2851,8 +2851,7 @@ static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
       __ LoadClassById(R5, kInstanceCidOrFunction);
       __ mov(kInstanceInstantiatorTypeArgumentsReg, kNullReg);
       __ LoadFieldFromOffset(
-          R5, R5,
-          target::Class::host_type_arguments_field_offset_in_words_offset(),
+          R5, R5, target::Class::type_arguments_field_offset_in_words_offset(),
           kWord);
       __ CompareImmediate(R5, target::Class::kNoTypeArguments);
       __ b(&has_no_type_arguments, EQ);
diff --git a/runtime/vm/compiler/stub_code_compiler_ia32.cc b/runtime/vm/compiler/stub_code_compiler_ia32.cc
index 6510cb519eba6..6556b7dfaf57d 100644
--- a/runtime/vm/compiler/stub_code_compiler_ia32.cc
+++ b/runtime/vm/compiler/stub_code_compiler_ia32.cc
@@ -2349,10 +2349,11 @@ static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
       Label has_no_type_arguments;
       __ LoadClassById(EDI, kInstanceCidOrFunction);
       __ movl(kInstanceInstantiatorTypeArgumentsReg, raw_null);
-      __ movl(EDI,
-              FieldAddress(
-                  EDI, target::Class::
-                           host_type_arguments_field_offset_in_words_offset()));
+      __ movl(
+          EDI,
+          FieldAddress(
+              EDI,
+              target::Class::type_arguments_field_offset_in_words_offset()));
       __ cmpl(EDI, Immediate(target::Class::kNoTypeArguments));
       __ j(EQUAL, &has_no_type_arguments, Assembler::kNearJump);
       __ movl(kInstanceInstantiatorTypeArgumentsReg,
diff --git a/runtime/vm/compiler/stub_code_compiler_x64.cc b/runtime/vm/compiler/stub_code_compiler_x64.cc
index a8cf49ddb9c39..3920de23b7b9b 100644
--- a/runtime/vm/compiler/stub_code_compiler_x64.cc
+++ b/runtime/vm/compiler/stub_code_compiler_x64.cc
@@ -2807,10 +2807,11 @@ static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
       Label has_no_type_arguments;
       __ LoadClassById(RDI, kInstanceCidOrFunction);
       __ movq(kInstanceInstantiatorTypeArgumentsReg, kNullReg);
-      __ movl(RDI,
-              FieldAddress(
-                  RDI, target::Class::
-                           host_type_arguments_field_offset_in_words_offset()));
+      __ movl(
+          RDI,
+          FieldAddress(
+              RDI,
+              target::Class::type_arguments_field_offset_in_words_offset()));
       __ cmpl(RDI, Immediate(target::Class::kNoTypeArguments));
       __ j(EQUAL, &has_no_type_arguments, Assembler::kNearJump);
       __ movq(kInstanceInstantiatorTypeArgumentsReg,
diff --git a/runtime/vm/dart_api_impl_test.cc b/runtime/vm/dart_api_impl_test.cc
index 23a083a5dab59..bc23cea0f6d71 100644
--- a/runtime/vm/dart_api_impl_test.cc
+++ b/runtime/vm/dart_api_impl_test.cc
@@ -4393,7 +4393,7 @@ TEST_CASE(DartAPI_InjectNativeFields3) {
   intptr_t header_size = sizeof(RawObject);
   EXPECT_EQ(
       Utils::RoundUp(((1 + 2) * kWordSize) + header_size, kObjectAlignment),
-      cls.host_instance_size());
+      cls.instance_size());
   EXPECT_EQ(kNumNativeFields, cls.num_native_fields());
 }
 
diff --git a/runtime/vm/datastream.h b/runtime/vm/datastream.h
index 77c74bcd1cfe4..da4c450145c46 100644
--- a/runtime/vm/datastream.h
+++ b/runtime/vm/datastream.h
@@ -72,10 +72,7 @@ class ReadStream : public ValueObject {
     current_ += len;
   }
 
-  template <typename T = intptr_t>
-  T ReadUnsigned() {
-    return Read<T>(kEndUnsignedByteMarker);
-  }
+  intptr_t ReadUnsigned() { return Read<intptr_t>(kEndUnsignedByteMarker); }
 
   intptr_t Position() const { return current_ - buffer_; }
   void SetPosition(intptr_t value) {
@@ -106,19 +103,6 @@ class ReadStream : public ValueObject {
     return Read<T>(kEndByteMarker);
   }
 
-  uword ReadWordWith32BitReads() {
-    constexpr intptr_t kNumBytesPerRead32 = sizeof(uint32_t);
-    constexpr intptr_t kNumRead32PerWord = sizeof(uword) / kNumBytesPerRead32;
-    constexpr intptr_t kNumBitsPerRead32 = kNumBytesPerRead32 * kBitsPerByte;
-
-    uword value = 0;
-    for (intptr_t j = 0; j < kNumRead32PerWord; j++) {
-      const auto partial_value = Raw<kNumBytesPerRead32, uint32_t>::Read(this);
-      value |= (static_cast<uword>(partial_value) << (j * kNumBitsPerRead32));
-    }
-    return value;
-  }
-
  private:
   int16_t Read16() { return Read16(kEndByteMarker); }
 
@@ -379,21 +363,8 @@ class WriteStream : public ValueObject {
     }
   };
 
-  void WriteWordWith32BitWrites(uword value) {
-    constexpr intptr_t kNumBytesPerWrite32 = sizeof(uint32_t);
-    constexpr intptr_t kNumWrite32PerWord = sizeof(uword) / kNumBytesPerWrite32;
-    constexpr intptr_t kNumBitsPerWrite32 = kNumBytesPerWrite32 * kBitsPerByte;
-
-    const uint32_t mask = Utils::NBitMask(kNumBitsPerWrite32);
-    for (intptr_t j = 0; j < kNumWrite32PerWord; j++) {
-      const uint32_t shifted_value = (value >> (j * kNumBitsPerWrite32));
-      Raw<kNumBytesPerWrite32, uint32_t>::Write(this, shifted_value & mask);
-    }
-  }
-
-  template <typename T>
-  void WriteUnsigned(T value) {
-    ASSERT(value >= 0);
+  void WriteUnsigned(intptr_t value) {
+    ASSERT((value >= 0) && (value <= kIntptrMax));
     while (value > kMaxUnsignedDataPerByte) {
       WriteByte(static_cast<uint8_t>(value & kByteMask));
       value = value >> kDataBitsPerByte;
diff --git a/runtime/vm/deferred_objects.cc b/runtime/vm/deferred_objects.cc
index 2072c77aa81c9..7238899e106ba 100644
--- a/runtime/vm/deferred_objects.cc
+++ b/runtime/vm/deferred_objects.cc
@@ -307,7 +307,7 @@ void DeferredObject::Fill() {
         // materialization of e.g. _ByteDataView objects which don't have
         // explicit fields in Dart (all accesses to the fields are done via
         // recognized native methods).
-        ASSERT(offset.Value() < cls.host_instance_size());
+        ASSERT(offset.Value() < cls.instance_size());
         obj.SetFieldAtOffset(offset.Value(), value);
         if (FLAG_trace_deoptimization_verbose) {
           OS::PrintErr("    null Field @ offset(%" Pd ") <- %s\n",
diff --git a/runtime/vm/heap/scavenger.cc b/runtime/vm/heap/scavenger.cc
index 0c15bb819afba..484821c6b4888 100644
--- a/runtime/vm/heap/scavenger.cc
+++ b/runtime/vm/heap/scavenger.cc
@@ -137,7 +137,7 @@ class ScavengerVisitor : public ObjectPointerVisitor {
     view->RecomputeDataFieldForInternalTypedData();
   }
 
-  virtual void VisitPointers(RawObject** first, RawObject** last) {
+  void VisitPointers(RawObject** first, RawObject** last) {
     ASSERT(Utils::IsAligned(first, sizeof(*first)));
     ASSERT(Utils::IsAligned(last, sizeof(*last)));
     for (RawObject** current = first; current <= last; current++) {
diff --git a/runtime/vm/interpreter.cc b/runtime/vm/interpreter.cc
index d59dbfec40923..7f2b3fb0037ca 100644
--- a/runtime/vm/interpreter.cc
+++ b/runtime/vm/interpreter.cc
@@ -126,9 +126,10 @@ class InterpreterHelpers {
     RawClass* instance_class =
         thread->isolate()->class_table()->At(GetClassId(instance));
     return instance_class->ptr()->num_type_arguments_ > 0
-               ? reinterpret_cast<RawTypeArguments**>(instance->ptr())
-                     [instance_class->ptr()
-                          ->host_type_arguments_field_offset_in_words_]
+               ? reinterpret_cast<RawTypeArguments**>(
+                     instance
+                         ->ptr())[instance_class->ptr()
+                                      ->type_arguments_field_offset_in_words_]
                : TypeArguments::null();
   }
 
@@ -1204,7 +1205,7 @@ bool Interpreter::AssertAssignable(Thread* thread,
       } else if (instance_class->ptr()->num_type_arguments_ > 0) {
         instance_type_arguments = reinterpret_cast<RawTypeArguments**>(
             instance->ptr())[instance_class->ptr()
-                                 ->host_type_arguments_field_offset_in_words_];
+                                 ->type_arguments_field_offset_in_words_];
       }
       parent_function_type_arguments =
           static_cast<RawTypeArguments*>(null_value);
@@ -2332,7 +2333,7 @@ RawObject* Interpreter::Call(RawFunction* function,
     BYTECODE(InitLateField, D);
     RawField* field = RAW_CAST(Field, LOAD_CONSTANT(rD + 1));
     RawInstance* instance = reinterpret_cast<RawInstance*>(SP[0]);
-    intptr_t offset_in_words = field->ptr()->host_offset_or_field_id_;
+    intptr_t offset_in_words = field->ptr()->offset_or_field_id_;
 
     instance->StorePointer(
         reinterpret_cast<RawObject**>(instance->ptr()) + offset_in_words,
@@ -2361,7 +2362,7 @@ RawObject* Interpreter::Call(RawFunction* function,
     BYTECODE(StoreStaticTOS, D);
     RawField* field = reinterpret_cast<RawField*>(LOAD_CONSTANT(rD));
     RawInstance* value = static_cast<RawInstance*>(*SP--);
-    intptr_t field_id = field->ptr()->host_offset_or_field_id_;
+    intptr_t field_id = field->ptr()->offset_or_field_id_;
     thread->field_table_values()[field_id] = value;
     DISPATCH();
   }
@@ -2369,7 +2370,7 @@ RawObject* Interpreter::Call(RawFunction* function,
   {
     BYTECODE(LoadStatic, D);
     RawField* field = reinterpret_cast<RawField*>(LOAD_CONSTANT(rD));
-    intptr_t field_id = field->ptr()->host_offset_or_field_id_;
+    intptr_t field_id = field->ptr()->offset_or_field_id_;
     RawInstance* value = thread->field_table_values()[field_id];
     ASSERT((value != Object::sentinel().raw()) &&
            (value != Object::transition_sentinel().raw()));
@@ -2382,7 +2383,7 @@ RawObject* Interpreter::Call(RawFunction* function,
     RawField* field = RAW_CAST(Field, LOAD_CONSTANT(rD + 1));
     RawInstance* instance = reinterpret_cast<RawInstance*>(SP[-1]);
     RawObject* value = reinterpret_cast<RawObject*>(SP[0]);
-    intptr_t offset_in_words = field->ptr()->host_offset_or_field_id_;
+    intptr_t offset_in_words = field->ptr()->offset_or_field_id_;
 
     if (InterpreterHelpers::FieldNeedsGuardUpdate(field, value)) {
       SP[1] = 0;  // Unused result of runtime call.
@@ -2557,7 +2558,7 @@ RawObject* Interpreter::Call(RawFunction* function,
     RawClass* cls = Class::RawCast(LOAD_CONSTANT(rD));
     if (LIKELY(InterpreterHelpers::IsFinalized(cls))) {
       const intptr_t class_id = cls->ptr()->id_;
-      const intptr_t instance_size = cls->ptr()->host_instance_size_in_words_
+      const intptr_t instance_size = cls->ptr()->instance_size_in_words_
                                      << kWordSizeLog2;
       RawObject* result;
       if (TryAllocate(thread, class_id, instance_size, &result)) {
@@ -2587,7 +2588,7 @@ RawObject* Interpreter::Call(RawFunction* function,
     RawTypeArguments* type_args = TypeArguments::RawCast(SP[-1]);
     if (LIKELY(InterpreterHelpers::IsFinalized(cls))) {
       const intptr_t class_id = cls->ptr()->id_;
-      const intptr_t instance_size = cls->ptr()->host_instance_size_in_words_
+      const intptr_t instance_size = cls->ptr()->instance_size_in_words_
                                      << kWordSizeLog2;
       RawObject* result;
       if (TryAllocate(thread, class_id, instance_size, &result)) {
@@ -2597,8 +2598,7 @@ RawObject* Interpreter::Call(RawFunction* function,
           *reinterpret_cast<RawObject**>(start + offset) = null_value;
         }
         const intptr_t type_args_offset =
-            cls->ptr()->host_type_arguments_field_offset_in_words_
-            << kWordSizeLog2;
+            cls->ptr()->type_arguments_field_offset_in_words_ << kWordSizeLog2;
         *reinterpret_cast<RawObject**>(start + type_args_offset) = type_args;
         *--SP = result;
         DISPATCH();
@@ -3168,7 +3168,7 @@ RawObject* Interpreter::Call(RawFunction* function,
 
     // Field object is cached in function's data_.
     RawField* field = reinterpret_cast<RawField*>(function->ptr()->data_);
-    intptr_t offset_in_words = field->ptr()->host_offset_or_field_id_;
+    intptr_t offset_in_words = field->ptr()->offset_or_field_id_;
 
     const intptr_t kArgc = 1;
     RawInstance* instance =
@@ -3188,7 +3188,7 @@ RawObject* Interpreter::Call(RawFunction* function,
       function = FrameFunction(FP);
       instance = reinterpret_cast<RawInstance*>(SP[2]);
       field = reinterpret_cast<RawField*>(SP[3]);
-      offset_in_words = field->ptr()->host_offset_or_field_id_;
+      offset_in_words = field->ptr()->offset_or_field_id_;
       value = reinterpret_cast<RawInstance**>(instance->ptr())[offset_in_words];
     }
 
@@ -3249,7 +3249,7 @@ RawObject* Interpreter::Call(RawFunction* function,
 
     // Field object is cached in function's data_.
     RawField* field = reinterpret_cast<RawField*>(function->ptr()->data_);
-    intptr_t offset_in_words = field->ptr()->host_offset_or_field_id_;
+    intptr_t offset_in_words = field->ptr()->offset_or_field_id_;
     const intptr_t kArgc = 2;
     RawInstance* instance =
         reinterpret_cast<RawInstance*>(FrameArguments(FP, kArgc)[0]);
@@ -3329,7 +3329,7 @@ RawObject* Interpreter::Call(RawFunction* function,
 
     // Field object is cached in function's data_.
     RawField* field = reinterpret_cast<RawField*>(function->ptr()->data_);
-    intptr_t field_id = field->ptr()->host_offset_or_field_id_;
+    intptr_t field_id = field->ptr()->offset_or_field_id_;
     RawInstance* value = thread->field_table_values()[field_id];
     if (value == Object::sentinel().raw() ||
         value == Object::transition_sentinel().raw()) {
@@ -3343,7 +3343,7 @@ RawObject* Interpreter::Call(RawFunction* function,
       function = FrameFunction(FP);
       field = reinterpret_cast<RawField*>(function->ptr()->data_);
       // The field is initialized by the runtime call, but not returned.
-      intptr_t field_id = field->ptr()->host_offset_or_field_id_;
+      intptr_t field_id = field->ptr()->offset_or_field_id_;
       value = thread->field_table_values()[field_id];
     }
 
diff --git a/runtime/vm/isolate_reload.cc b/runtime/vm/isolate_reload.cc
index 981972a329b7b..6b7d2687ab64e 100644
--- a/runtime/vm/isolate_reload.cc
+++ b/runtime/vm/isolate_reload.cc
@@ -110,9 +110,9 @@ InstanceMorpher* InstanceMorpher::CreateFromClassDescriptors(
 
   if (from.NumTypeArguments() > 0) {
     // Add copying of the optional type argument field.
-    intptr_t from_offset = from.host_type_arguments_field_offset();
+    intptr_t from_offset = from.type_arguments_field_offset();
     ASSERT(from_offset != Class::kNoTypeArguments);
-    intptr_t to_offset = to.host_type_arguments_field_offset();
+    intptr_t to_offset = to.type_arguments_field_offset();
     ASSERT(to_offset != Class::kNoTypeArguments);
     mapping->Add(from_offset);
     mapping->Add(to_offset);
@@ -152,8 +152,8 @@ InstanceMorpher* InstanceMorpher::CreateFromClassDescriptors(
       from_name = from_field.name();
       if (from_name.Equals(to_name)) {
         // Success
-        mapping->Add(from_field.HostOffset());
-        mapping->Add(to_field.HostOffset());
+        mapping->Add(from_field.Offset());
+        mapping->Add(to_field.Offset());
         // Field did exist in old class deifnition.
         new_field = false;
       }
@@ -163,7 +163,7 @@ InstanceMorpher* InstanceMorpher::CreateFromClassDescriptors(
       const Field& field = Field::Handle(to_field.raw());
       field.set_needs_load_guard(true);
       field.set_is_unboxing_candidate(false);
-      new_fields_offsets->Add(field.HostOffset());
+      new_fields_offsets->Add(field.Offset());
     }
   }
 
@@ -1247,9 +1247,8 @@ void IsolateGroupReloadContext::FindModifiedSources(
       uri = script.url();
       const bool dart_scheme = uri.StartsWith(Symbols::DartScheme());
       if (dart_scheme) {
-        // If a user-defined class mixes in a mixin from dart:*, it's list of
-        // scripts will have a dart:* script as well. We don't consider those
-        // during reload.
+        // If a user-defined class mixes in a mixin from dart:*, it's list of scripts will have
+        // a dart:* script as well. We don't consider those during reload.
         continue;
       }
       if (ContainsScriptUri(modified_sources_uris, uri.ToCString())) {
diff --git a/runtime/vm/kernel_loader.cc b/runtime/vm/kernel_loader.cc
index bd81e37acbfb6..49ef53b96757e 100644
--- a/runtime/vm/kernel_loader.cc
+++ b/runtime/vm/kernel_loader.cc
@@ -8,7 +8,6 @@
 
 #include <memory>
 
-#include "vm/compiler/backend/flow_graph_compiler.h"
 #include "vm/compiler/frontend/constant_reader.h"
 #include "vm/compiler/frontend/kernel_translation_helper.h"
 #include "vm/dart_api_impl.h"
@@ -949,17 +948,6 @@ void KernelLoader::ReadInferredType(const Field& field,
   field.set_guarded_cid(type.cid);
   field.set_is_nullable(type.IsNullable());
   field.set_guarded_list_length(Field::kNoFixedLength);
-  if (FLAG_precompiled_mode) {
-    field.set_is_unboxing_candidate(
-        !field.is_late() && !field.is_static() &&
-        ((field.guarded_cid() == kDoubleCid &&
-          FlowGraphCompiler::SupportsUnboxedDoubles()) ||
-         (field.guarded_cid() == kFloat32x4Cid &&
-          FlowGraphCompiler::SupportsUnboxedSimd128()) ||
-         (field.guarded_cid() == kFloat64x2Cid &&
-          FlowGraphCompiler::SupportsUnboxedSimd128())) &&
-        !field.is_nullable());
-  }
 }
 
 void KernelLoader::CheckForInitializer(const Field& field) {
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index ca5e620797777..2d23770aa6ad9 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -693,19 +693,14 @@ void Object::Init(Isolate* isolate) {
     // to lookup class class in the class table where it is not registered yet.
     cls.raw_ = class_class_;
     ASSERT(builtin_vtables_[kClassCid] == fake.vtable());
-    cls.set_instance_size(
-        Class::InstanceSize(),
-        compiler::target::RoundedAllocationSize(RTN::Class::InstanceSize()));
-    const intptr_t host_next_field_offset = Class::NextFieldOffset();
-    const intptr_t target_next_field_offset = RTN::Class::NextFieldOffset();
-    cls.set_next_field_offset(host_next_field_offset, target_next_field_offset);
+    cls.set_instance_size(Class::InstanceSize());
+    cls.set_next_field_offset(Class::NextFieldOffset());
     cls.set_id(Class::kClassId);
     cls.set_state_bits(0);
     cls.set_is_finalized();
     cls.set_is_declaration_loaded();
     cls.set_is_type_finalized();
-    cls.set_type_arguments_field_offset_in_words(Class::kNoTypeArguments,
-                                                 RTN::Class::kNoTypeArguments);
+    cls.set_type_arguments_field_offset_in_words(Class::kNoTypeArguments);
     cls.set_num_type_arguments(0);
     cls.set_num_native_fields(0);
     cls.InitEmptyFields();
@@ -713,23 +708,19 @@ void Object::Init(Isolate* isolate) {
   }
 
   // Allocate and initialize the null class.
-  cls = Class::New<Instance, RTN::Instance>(kNullCid, isolate);
+  cls = Class::New<Instance>(kNullCid, isolate);
   cls.set_num_type_arguments(0);
   isolate->object_store()->set_null_class(cls);
 
   // Allocate and initialize the free list element class.
-  cls =
-      Class::New<FreeListElement::FakeInstance,
-                 RTN::FreeListElement::FakeInstance>(kFreeListElement, isolate);
+  cls = Class::New<FreeListElement::FakeInstance>(kFreeListElement, isolate);
   cls.set_num_type_arguments(0);
   cls.set_is_finalized();
   cls.set_is_declaration_loaded();
   cls.set_is_type_finalized();
 
   // Allocate and initialize the forwarding corpse class.
-  cls = Class::New<ForwardingCorpse::FakeInstance,
-                   RTN::ForwardingCorpse::FakeInstance>(kForwardingCorpse,
-                                                        isolate);
+  cls = Class::New<ForwardingCorpse::FakeInstance>(kForwardingCorpse, isolate);
   cls.set_num_type_arguments(0);
   cls.set_is_finalized();
   cls.set_is_declaration_loaded();
@@ -753,136 +744,132 @@ void Object::Init(Isolate* isolate) {
   }
 
   // Allocate the remaining VM internal classes.
-  cls = Class::New<TypeArguments, RTN::TypeArguments>(isolate);
+  cls = Class::New<TypeArguments>(isolate);
   type_arguments_class_ = cls.raw();
 
-  cls = Class::New<PatchClass, RTN::PatchClass>(isolate);
+  cls = Class::New<PatchClass>(isolate);
   patch_class_class_ = cls.raw();
 
-  cls = Class::New<Function, RTN::Function>(isolate);
+  cls = Class::New<Function>(isolate);
   function_class_ = cls.raw();
 
-  cls = Class::New<ClosureData, RTN::ClosureData>(isolate);
+  cls = Class::New<ClosureData>(isolate);
   closure_data_class_ = cls.raw();
 
-  cls = Class::New<SignatureData, RTN::SignatureData>(isolate);
+  cls = Class::New<SignatureData>(isolate);
   signature_data_class_ = cls.raw();
 
-  cls = Class::New<RedirectionData, RTN::RedirectionData>(isolate);
+  cls = Class::New<RedirectionData>(isolate);
   redirection_data_class_ = cls.raw();
 
-  cls = Class::New<FfiTrampolineData, RTN::FfiTrampolineData>(isolate);
+  cls = Class::New<FfiTrampolineData>(isolate);
   ffi_trampoline_data_class_ = cls.raw();
 
-  cls = Class::New<Field, RTN::Field>(isolate);
+  cls = Class::New<Field>(isolate);
   field_class_ = cls.raw();
 
-  cls = Class::New<Script, RTN::Script>(isolate);
+  cls = Class::New<Script>(isolate);
   script_class_ = cls.raw();
 
-  cls = Class::New<Library, RTN::Library>(isolate);
+  cls = Class::New<Library>(isolate);
   library_class_ = cls.raw();
 
-  cls = Class::New<Namespace, RTN::Namespace>(isolate);
+  cls = Class::New<Namespace>(isolate);
   namespace_class_ = cls.raw();
 
-  cls = Class::New<KernelProgramInfo, RTN::KernelProgramInfo>(isolate);
+  cls = Class::New<KernelProgramInfo>(isolate);
   kernel_program_info_class_ = cls.raw();
 
-  cls = Class::New<Code, RTN::Code>(isolate);
+  cls = Class::New<Code>(isolate);
   code_class_ = cls.raw();
 
-  cls = Class::New<Bytecode, RTN::Bytecode>(isolate);
+  cls = Class::New<Bytecode>(isolate);
   bytecode_class_ = cls.raw();
 
-  cls = Class::New<Instructions, RTN::Instructions>(isolate);
+  cls = Class::New<Instructions>(isolate);
   instructions_class_ = cls.raw();
 
-  cls = Class::New<ObjectPool, RTN::ObjectPool>(isolate);
+  cls = Class::New<ObjectPool>(isolate);
   object_pool_class_ = cls.raw();
 
-  cls = Class::New<PcDescriptors, RTN::PcDescriptors>(isolate);
+  cls = Class::New<PcDescriptors>(isolate);
   pc_descriptors_class_ = cls.raw();
 
-  cls = Class::New<CodeSourceMap, RTN::CodeSourceMap>(isolate);
+  cls = Class::New<CodeSourceMap>(isolate);
   code_source_map_class_ = cls.raw();
 
-  cls = Class::New<CompressedStackMaps, RTN::CompressedStackMaps>(isolate);
+  cls = Class::New<CompressedStackMaps>(isolate);
   compressed_stackmaps_class_ = cls.raw();
 
-  cls = Class::New<LocalVarDescriptors, RTN::LocalVarDescriptors>(isolate);
+  cls = Class::New<LocalVarDescriptors>(isolate);
   var_descriptors_class_ = cls.raw();
 
-  cls = Class::New<ExceptionHandlers, RTN::ExceptionHandlers>(isolate);
+  cls = Class::New<ExceptionHandlers>(isolate);
   exception_handlers_class_ = cls.raw();
 
-  cls = Class::New<Context, RTN::Context>(isolate);
+  cls = Class::New<Context>(isolate);
   context_class_ = cls.raw();
 
-  cls = Class::New<ContextScope, RTN::ContextScope>(isolate);
+  cls = Class::New<ContextScope>(isolate);
   context_scope_class_ = cls.raw();
 
-  cls = Class::New<ParameterTypeCheck, RTN::ParameterTypeCheck>(isolate);
+  cls = Class::New<ParameterTypeCheck>(isolate);
   dyncalltypecheck_class_ = cls.raw();
 
-  cls = Class::New<SingleTargetCache, RTN::SingleTargetCache>(isolate);
+  cls = Class::New<SingleTargetCache>(isolate);
   singletargetcache_class_ = cls.raw();
 
-  cls = Class::New<UnlinkedCall, RTN::UnlinkedCall>(isolate);
+  cls = Class::New<UnlinkedCall>(isolate);
   unlinkedcall_class_ = cls.raw();
 
-  cls =
-      Class::New<MonomorphicSmiableCall, RTN::MonomorphicSmiableCall>(isolate);
+  cls = Class::New<MonomorphicSmiableCall>(isolate);
   monomorphicsmiablecall_class_ = cls.raw();
 
-  cls = Class::New<ICData, RTN::ICData>(isolate);
+  cls = Class::New<ICData>(isolate);
   icdata_class_ = cls.raw();
 
-  cls = Class::New<MegamorphicCache, RTN::MegamorphicCache>(isolate);
+  cls = Class::New<MegamorphicCache>(isolate);
   megamorphic_cache_class_ = cls.raw();
 
-  cls = Class::New<SubtypeTestCache, RTN::SubtypeTestCache>(isolate);
+  cls = Class::New<SubtypeTestCache>(isolate);
   subtypetestcache_class_ = cls.raw();
 
-  cls = Class::New<ApiError, RTN::ApiError>(isolate);
+  cls = Class::New<ApiError>(isolate);
   api_error_class_ = cls.raw();
 
-  cls = Class::New<LanguageError, RTN::LanguageError>(isolate);
+  cls = Class::New<LanguageError>(isolate);
   language_error_class_ = cls.raw();
 
-  cls = Class::New<UnhandledException, RTN::UnhandledException>(isolate);
+  cls = Class::New<UnhandledException>(isolate);
   unhandled_exception_class_ = cls.raw();
 
-  cls = Class::New<UnwindError, RTN::UnwindError>(isolate);
+  cls = Class::New<UnwindError>(isolate);
   unwind_error_class_ = cls.raw();
 
   ASSERT(class_class() != null_);
 
   // Pre-allocate classes in the vm isolate so that we can for example create a
   // symbol table and populate it with some frequently used strings as symbols.
-  cls = Class::New<Array, RTN::Array>(isolate);
+  cls = Class::New<Array>(isolate);
   isolate->object_store()->set_array_class(cls);
-  cls.set_type_arguments_field_offset(Array::type_arguments_offset(),
-                                      RTN::Array::type_arguments_offset());
+  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
   cls.set_num_type_arguments(1);
-  cls = Class::New<Array, RTN::Array>(kImmutableArrayCid, isolate);
+  cls = Class::New<Array>(kImmutableArrayCid, isolate);
   isolate->object_store()->set_immutable_array_class(cls);
-  cls.set_type_arguments_field_offset(Array::type_arguments_offset(),
-                                      RTN::Array::type_arguments_offset());
+  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
   cls.set_num_type_arguments(1);
-  cls = Class::New<GrowableObjectArray, RTN::GrowableObjectArray>(isolate);
+  cls = Class::New<GrowableObjectArray>(isolate);
   isolate->object_store()->set_growable_object_array_class(cls);
   cls.set_type_arguments_field_offset(
-      GrowableObjectArray::type_arguments_offset(),
-      RTN::GrowableObjectArray::type_arguments_offset());
+      GrowableObjectArray::type_arguments_offset());
   cls.set_num_type_arguments(1);
   cls = Class::NewStringClass(kOneByteStringCid, isolate);
   isolate->object_store()->set_one_byte_string_class(cls);
   cls = Class::NewStringClass(kTwoByteStringCid, isolate);
   isolate->object_store()->set_two_byte_string_class(cls);
-  cls = Class::New<Mint, RTN::Mint>(isolate);
+  cls = Class::New<Mint>(isolate);
   isolate->object_store()->set_mint_class(cls);
-  cls = Class::New<Double, RTN::Double>(isolate);
+  cls = Class::New<Double>(isolate);
   isolate->object_store()->set_double_class(cls);
 
   // Ensure that class kExternalTypedDataUint8ArrayCid is registered as we
@@ -1004,7 +991,7 @@ void Object::Init(Isolate* isolate) {
   // as we do not have any VM isolate snapshot at this time.
   *vm_isolate_snapshot_object_table_ = Object::empty_array().raw();
 
-  cls = Class::New<Instance, RTN::Instance>(kDynamicCid, isolate);
+  cls = Class::New<Instance>(kDynamicCid, isolate);
   cls.set_is_abstract();
   cls.set_num_type_arguments(0);
   cls.set_is_finalized();
@@ -1012,21 +999,21 @@ void Object::Init(Isolate* isolate) {
   cls.set_is_type_finalized();
   dynamic_class_ = cls.raw();
 
-  cls = Class::New<Instance, RTN::Instance>(kVoidCid, isolate);
+  cls = Class::New<Instance>(kVoidCid, isolate);
   cls.set_num_type_arguments(0);
   cls.set_is_finalized();
   cls.set_is_declaration_loaded();
   cls.set_is_type_finalized();
   void_class_ = cls.raw();
 
-  cls = Class::New<Instance, RTN::Instance>(kNeverCid, isolate);
+  cls = Class::New<Instance>(kNeverCid, isolate);
   cls.set_num_type_arguments(0);
   cls.set_is_finalized();
   cls.set_is_declaration_loaded();
   cls.set_is_type_finalized();
   never_class_ = cls.raw();
 
-  cls = Class::New<Type, RTN::Type>(isolate);
+  cls = Class::New<Type>(isolate);
   cls.set_is_finalized();
   cls.set_is_declaration_loaded();
   cls.set_is_type_finalized();
@@ -1058,7 +1045,7 @@ void Object::Init(Isolate* isolate) {
   cls.SetFunctions(Object::empty_array());
 
   // Allocate and initialize singleton true and false boolean objects.
-  cls = Class::New<Bool, RTN::Bool>(isolate);
+  cls = Class::New<Bool>(isolate);
   isolate->object_store()->set_bool_class(cls);
   *bool_true_ = Bool::New(true);
   *bool_false_ = Bool::New(false);
@@ -1584,7 +1571,7 @@ RawError* Object::Init(Isolate* isolate,
 
     // All RawArray fields will be initialized to an empty array, therefore
     // initialize array class first.
-    cls = Class::New<Array, RTN::Array>(isolate);
+    cls = Class::New<Array>(isolate);
     object_store->set_array_class(cls);
 
     // VM classes that are parameterized (Array, ImmutableArray,
@@ -1592,17 +1579,15 @@ RawError* Object::Init(Isolate* isolate,
     // CalculateFieldOffsets() is not called, so we need to set the offset of
     // their type_arguments_ field, which is explicitly declared in their
     // respective Raw* classes.
-    cls.set_type_arguments_field_offset(Array::type_arguments_offset(),
-                                        RTN::Array::type_arguments_offset());
+    cls.set_type_arguments_field_offset(Array::type_arguments_offset());
     cls.set_num_type_arguments(1);
 
     // Set up the growable object array class (Has to be done after the array
     // class is setup as one of its field is an array object).
-    cls = Class::New<GrowableObjectArray, RTN::GrowableObjectArray>(isolate);
+    cls = Class::New<GrowableObjectArray>(isolate);
     object_store->set_growable_object_array_class(cls);
     cls.set_type_arguments_field_offset(
-        GrowableObjectArray::type_arguments_offset(),
-        RTN::GrowableObjectArray::type_arguments_offset());
+        GrowableObjectArray::type_arguments_offset());
     cls.set_num_type_arguments(1);
 
     // Initialize hash set for canonical types.
@@ -1618,14 +1603,13 @@ RawError* Object::Init(Isolate* isolate,
     object_store->set_canonical_type_arguments(array);
 
     // Setup type class early in the process.
-    const Class& type_cls =
-        Class::Handle(zone, Class::New<Type, RTN::Type>(isolate));
+    const Class& type_cls = Class::Handle(zone, Class::New<Type>(isolate));
     const Class& type_ref_cls =
-        Class::Handle(zone, Class::New<TypeRef, RTN::TypeRef>(isolate));
-    const Class& type_parameter_cls = Class::Handle(
-        zone, Class::New<TypeParameter, RTN::TypeParameter>(isolate));
-    const Class& library_prefix_cls = Class::Handle(
-        zone, Class::New<LibraryPrefix, RTN::LibraryPrefix>(isolate));
+        Class::Handle(zone, Class::New<TypeRef>(isolate));
+    const Class& type_parameter_cls =
+        Class::Handle(zone, Class::New<TypeParameter>(isolate));
+    const Class& library_prefix_cls =
+        Class::Handle(zone, Class::New<LibraryPrefix>(isolate));
 
     // Pre-allocate the OneByteString class needed by the symbol table.
     cls = Class::NewStringClass(kOneByteStringCid, isolate);
@@ -1682,10 +1666,9 @@ RawError* Object::Init(Isolate* isolate,
     RegisterPrivateClass(cls, Symbols::_GrowableList(), core_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<Array, RTN::Array>(kImmutableArrayCid, isolate);
+    cls = Class::New<Array>(kImmutableArrayCid, isolate);
     object_store->set_immutable_array_class(cls);
-    cls.set_type_arguments_field_offset(Array::type_arguments_offset(),
-                                        RTN::Array::type_arguments_offset());
+    cls.set_type_arguments_field_offset(Array::type_arguments_offset());
     cls.set_num_type_arguments(1);
     ASSERT(object_store->immutable_array_class() !=
            object_store->array_class());
@@ -1724,31 +1707,30 @@ RawError* Object::Init(Isolate* isolate,
     ASSERT(!isolate_lib.IsNull());
     ASSERT(isolate_lib.raw() == Library::IsolateLibrary());
 
-    cls = Class::New<Capability, RTN::Capability>(isolate);
+    cls = Class::New<Capability>(isolate);
     RegisterPrivateClass(cls, Symbols::_CapabilityImpl(), isolate_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<ReceivePort, RTN::ReceivePort>(isolate);
+    cls = Class::New<ReceivePort>(isolate);
     RegisterPrivateClass(cls, Symbols::_RawReceivePortImpl(), isolate_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<SendPort, RTN::SendPort>(isolate);
+    cls = Class::New<SendPort>(isolate);
     RegisterPrivateClass(cls, Symbols::_SendPortImpl(), isolate_lib);
     pending_classes.Add(cls);
 
-    cls =
-        Class::New<TransferableTypedData, RTN::TransferableTypedData>(isolate);
+    cls = Class::New<TransferableTypedData>(isolate);
     RegisterPrivateClass(cls, Symbols::_TransferableTypedDataImpl(),
                          isolate_lib);
     pending_classes.Add(cls);
 
     const Class& stacktrace_cls =
-        Class::Handle(zone, Class::New<StackTrace, RTN::StackTrace>(isolate));
+        Class::Handle(zone, Class::New<StackTrace>(isolate));
     RegisterPrivateClass(stacktrace_cls, Symbols::_StackTrace(), core_lib);
     pending_classes.Add(stacktrace_cls);
     // Super type set below, after Object is allocated.
 
-    cls = Class::New<RegExp, RTN::RegExp>(isolate);
+    cls = Class::New<RegExp>(isolate);
     RegisterPrivateClass(cls, Symbols::_RegExp(), core_lib);
     pending_classes.Add(cls);
 
@@ -1758,7 +1740,7 @@ RawError* Object::Init(Isolate* isolate,
     // The script and token index of these pre-allocated classes is set up in
     // the parser when the corelib script is compiled (see
     // Parser::ParseClassDefinition).
-    cls = Class::New<Instance, RTN::Instance>(kInstanceCid, isolate);
+    cls = Class::New<Instance>(kInstanceCid, isolate);
     object_store->set_object_class(cls);
     cls.set_name(Symbols::Object());
     cls.set_num_type_arguments(0);
@@ -1772,12 +1754,12 @@ RawError* Object::Init(Isolate* isolate,
     type = type.ToNullability(Nullability::kNonNullable, Heap::kOld);
     object_store->set_non_nullable_object_type(type);
 
-    cls = Class::New<Bool, RTN::Bool>(isolate);
+    cls = Class::New<Bool>(isolate);
     object_store->set_bool_class(cls);
     RegisterClass(cls, Symbols::Bool(), core_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<Instance, RTN::Instance>(kNullCid, isolate);
+    cls = Class::New<Instance>(kNullCid, isolate);
     object_store->set_null_class(cls);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
@@ -1799,33 +1781,33 @@ RawError* Object::Init(Isolate* isolate,
                          core_lib);
     pending_classes.Add(type_parameter_cls);
 
-    cls = Class::New<Integer, RTN::Integer>(isolate);
+    cls = Class::New<Integer>(isolate);
     object_store->set_integer_implementation_class(cls);
     RegisterPrivateClass(cls, Symbols::_IntegerImplementation(), core_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<Smi, RTN::Smi>(isolate);
+    cls = Class::New<Smi>(isolate);
     object_store->set_smi_class(cls);
     RegisterPrivateClass(cls, Symbols::_Smi(), core_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<Mint, RTN::Mint>(isolate);
+    cls = Class::New<Mint>(isolate);
     object_store->set_mint_class(cls);
     RegisterPrivateClass(cls, Symbols::_Mint(), core_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<Double, RTN::Double>(isolate);
+    cls = Class::New<Double>(isolate);
     object_store->set_double_class(cls);
     RegisterPrivateClass(cls, Symbols::_Double(), core_lib);
     pending_classes.Add(cls);
 
     // Class that represents the Dart class _Closure and C++ class Closure.
-    cls = Class::New<Closure, RTN::Closure>(isolate);
+    cls = Class::New<Closure>(isolate);
     object_store->set_closure_class(cls);
     RegisterPrivateClass(cls, Symbols::_Closure(), core_lib);
     pending_classes.Add(cls);
 
-    cls = Class::New<WeakProperty, RTN::WeakProperty>(isolate);
+    cls = Class::New<WeakProperty>(isolate);
     object_store->set_weak_property_class(cls);
     RegisterPrivateClass(cls, Symbols::_WeakProperty(), core_lib);
 
@@ -1842,7 +1824,7 @@ RawError* Object::Init(Isolate* isolate,
     ASSERT(!lib.IsNull());
     ASSERT(lib.raw() == Library::MirrorsLibrary());
 
-    cls = Class::New<MirrorReference, RTN::MirrorReference>(isolate);
+    cls = Class::New<MirrorReference>(isolate);
     RegisterPrivateClass(cls, Symbols::_MirrorReference(), lib);
 #endif
 
@@ -1858,11 +1840,9 @@ RawError* Object::Init(Isolate* isolate,
     object_store->set_bootstrap_library(ObjectStore::kCollection, lib);
     ASSERT(!lib.IsNull());
     ASSERT(lib.raw() == Library::CollectionLibrary());
-    cls = Class::New<LinkedHashMap, RTN::LinkedHashMap>(isolate);
+    cls = Class::New<LinkedHashMap>(isolate);
     object_store->set_linked_hash_map_class(cls);
-    cls.set_type_arguments_field_offset(
-        LinkedHashMap::type_arguments_offset(),
-        RTN::LinkedHashMap::type_arguments_offset());
+    cls.set_type_arguments_field_offset(LinkedHashMap::type_arguments_offset());
     cls.set_num_type_arguments(2);
     RegisterPrivateClass(cls, Symbols::_LinkedHashMap(), lib);
     pending_classes.Add(cls);
@@ -1878,7 +1858,7 @@ RawError* Object::Init(Isolate* isolate,
     object_store->set_bootstrap_library(ObjectStore::kDeveloper, lib);
     ASSERT(!lib.IsNull());
     ASSERT(lib.raw() == Library::DeveloperLibrary());
-    cls = Class::New<UserTag, RTN::UserTag>(isolate);
+    cls = Class::New<UserTag>(isolate);
     RegisterPrivateClass(cls, Symbols::_UserTag(), lib);
     pending_classes.Add(cls);
 
@@ -1921,10 +1901,10 @@ RawError* Object::Init(Isolate* isolate,
                                          isolate);                             \
   RegisterPrivateClass(cls, Symbols::_External##clazz(), lib);
 
-    cls = Class::New<Instance, RTN::Instance>(kByteBufferCid, isolate,
-                                              /*register_class=*/false);
-    cls.set_instance_size(0, 0);
-    cls.set_next_field_offset(-kWordSize, -compiler::target::kWordSize);
+    cls =
+        Class::New<Instance>(kByteBufferCid, isolate, /*register_class=*/false);
+    cls.set_instance_size(0);
+    cls.set_next_field_offset(-kWordSize);
     isolate->RegisterClass(cls);
     RegisterPrivateClass(cls, Symbols::_ByteBuffer(), lib);
     pending_classes.Add(cls);
@@ -1932,42 +1912,39 @@ RawError* Object::Init(Isolate* isolate,
     CLASS_LIST_TYPED_DATA(REGISTER_EXT_TYPED_DATA_CLASS);
 #undef REGISTER_EXT_TYPED_DATA_CLASS
     // Register Float32x4, Int32x4, and Float64x2 in the object store.
-    cls = Class::New<Float32x4, RTN::Float32x4>(isolate);
+    cls = Class::New<Float32x4>(isolate);
     RegisterPrivateClass(cls, Symbols::_Float32x4(), lib);
     pending_classes.Add(cls);
     object_store->set_float32x4_class(cls);
 
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     RegisterClass(cls, Symbols::Float32x4(), lib);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
     type = Type::NewNonParameterizedType(cls);
     object_store->set_float32x4_type(type);
 
-    cls = Class::New<Int32x4, RTN::Int32x4>(isolate);
+    cls = Class::New<Int32x4>(isolate);
     RegisterPrivateClass(cls, Symbols::_Int32x4(), lib);
     pending_classes.Add(cls);
     object_store->set_int32x4_class(cls);
 
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     RegisterClass(cls, Symbols::Int32x4(), lib);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
     type = Type::NewNonParameterizedType(cls);
     object_store->set_int32x4_type(type);
 
-    cls = Class::New<Float64x2, RTN::Float64x2>(isolate);
+    cls = Class::New<Float64x2>(isolate);
     RegisterPrivateClass(cls, Symbols::_Float64x2(), lib);
     pending_classes.Add(cls);
     object_store->set_float64x2_class(cls);
 
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     RegisterClass(cls, Symbols::Float64x2(), lib);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
@@ -1981,9 +1958,8 @@ RawError* Object::Init(Isolate* isolate,
 
     // Abstract class that represents the Dart class Type.
     // Note that this class is implemented by Dart class _AbstractType.
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
     RegisterClass(cls, Symbols::Type(), core_lib);
@@ -1992,9 +1968,8 @@ RawError* Object::Init(Isolate* isolate,
     object_store->set_type_type(type);
 
     // Abstract class that represents the Dart class Function.
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
     RegisterClass(cls, Symbols::Function(), core_lib);
@@ -2006,7 +1981,7 @@ RawError* Object::Init(Isolate* isolate,
     type = type.ToNullability(Nullability::kNonNullable, Heap::kOld);
     object_store->set_non_nullable_function_type(type);
 
-    cls = Class::New<Number, RTN::Number>(isolate);
+    cls = Class::New<Number>(isolate);
     RegisterClass(cls, Symbols::Number(), core_lib);
     pending_classes.Add(cls);
     type = Type::NewNonParameterizedType(cls);
@@ -2016,9 +1991,8 @@ RawError* Object::Init(Isolate* isolate,
     type = type.ToNullability(Nullability::kNonNullable, Heap::kOld);
     object_store->set_non_nullable_number_type(type);
 
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     RegisterClass(cls, Symbols::Int(), core_lib);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
@@ -2030,9 +2004,8 @@ RawError* Object::Init(Isolate* isolate,
     type = type.ToNullability(Nullability::kNonNullable, Heap::kOld);
     object_store->set_non_nullable_int_type(type);
 
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     RegisterClass(cls, Symbols::Double(), core_lib);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
@@ -2045,9 +2018,8 @@ RawError* Object::Init(Isolate* isolate,
     object_store->set_non_nullable_double_type(type);
 
     name = Symbols::_String().raw();
-    cls = Class::New<Instance, RTN::Instance>(kIllegalCid, isolate,
-                                              /*register_class=*/true,
-                                              /*is_abstract=*/true);
+    cls = Class::New<Instance>(kIllegalCid, isolate, /*register_class=*/true,
+                               /*is_abstract=*/true);
     RegisterClass(cls, name, core_lib);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
@@ -2198,7 +2170,7 @@ RawError* Object::Init(Isolate* isolate,
     }
     object_store->set_bootstrap_library(ObjectStore::kFfi, lib);
 
-    cls = Class::New<Instance, RTN::Instance>(kFfiNativeTypeCid, isolate);
+    cls = Class::New<Instance>(kFfiNativeTypeCid, isolate);
     cls.set_num_type_arguments(0);
     cls.set_is_prefinalized();
     pending_classes.Add(cls);
@@ -2206,7 +2178,7 @@ RawError* Object::Init(Isolate* isolate,
     RegisterClass(cls, Symbols::FfiNativeType(), lib);
 
 #define REGISTER_FFI_TYPE_MARKER(clazz)                                        \
-  cls = Class::New<Instance, RTN::Instance>(kFfi##clazz##Cid, isolate);        \
+  cls = Class::New<Instance>(kFfi##clazz##Cid, isolate);                       \
   cls.set_num_type_arguments(0);                                               \
   cls.set_is_prefinalized();                                                   \
   pending_classes.Add(cls);                                                    \
@@ -2214,9 +2186,8 @@ RawError* Object::Init(Isolate* isolate,
     CLASS_LIST_FFI_TYPE_MARKER(REGISTER_FFI_TYPE_MARKER);
 #undef REGISTER_FFI_TYPE_MARKER
 
-    cls = Class::New<Instance, RTN::Instance>(kFfiNativeFunctionCid, isolate);
-    cls.set_type_arguments_field_offset(Pointer::type_arguments_offset(),
-                                        RTN::Pointer::type_arguments_offset());
+    cls = Class::New<Instance>(kFfiNativeFunctionCid, isolate);
+    cls.set_type_arguments_field_offset(Pointer::type_arguments_offset());
     cls.set_num_type_arguments(1);
     cls.set_is_prefinalized();
     pending_classes.Add(cls);
@@ -2227,11 +2198,8 @@ RawError* Object::Init(Isolate* isolate,
     pending_classes.Add(cls);
     RegisterClass(cls, Symbols::FfiPointer(), lib);
 
-    cls = Class::New<DynamicLibrary, RTN::DynamicLibrary>(kFfiDynamicLibraryCid,
-                                                          isolate);
-    cls.set_instance_size(DynamicLibrary::InstanceSize(),
-                          compiler::target::RoundedAllocationSize(
-                              RTN::DynamicLibrary::InstanceSize()));
+    cls = Class::New<DynamicLibrary>(kFfiDynamicLibraryCid, isolate);
+    cls.set_instance_size(DynamicLibrary::InstanceSize());
     cls.set_is_prefinalized();
     pending_classes.Add(cls);
     RegisterClass(cls, Symbols::FfiDynamicLibrary(), lib);
@@ -2245,7 +2213,7 @@ RawError* Object::Init(Isolate* isolate,
     object_store->set_bootstrap_library(ObjectStore::kWasm, lib);
 
 #define REGISTER_WASM_TYPE(clazz)                                              \
-  cls = Class::New<Instance, RTN::Instance>(k##clazz##Cid, isolate);           \
+  cls = Class::New<Instance>(k##clazz##Cid, isolate);                          \
   cls.set_num_type_arguments(0);                                               \
   cls.set_is_prefinalized();                                                   \
   pending_classes.Add(cls);                                                    \
@@ -2295,33 +2263,33 @@ RawError* Object::Init(Isolate* isolate,
     // stored in the object store. Yet we still need to create their Class
     // object so that they get put into the class_table (as a side effect of
     // Class::New()).
-    cls = Class::New<Instance, RTN::Instance>(kInstanceCid, isolate);
+    cls = Class::New<Instance>(kInstanceCid, isolate);
     object_store->set_object_class(cls);
 
-    cls = Class::New<LibraryPrefix, RTN::LibraryPrefix>(isolate);
-    cls = Class::New<Type, RTN::Type>(isolate);
-    cls = Class::New<TypeRef, RTN::TypeRef>(isolate);
-    cls = Class::New<TypeParameter, RTN::TypeParameter>(isolate);
+    cls = Class::New<LibraryPrefix>(isolate);
+    cls = Class::New<Type>(isolate);
+    cls = Class::New<TypeRef>(isolate);
+    cls = Class::New<TypeParameter>(isolate);
 
-    cls = Class::New<Array, RTN::Array>(isolate);
+    cls = Class::New<Array>(isolate);
     object_store->set_array_class(cls);
 
-    cls = Class::New<Array, RTN::Array>(kImmutableArrayCid, isolate);
+    cls = Class::New<Array>(kImmutableArrayCid, isolate);
     object_store->set_immutable_array_class(cls);
 
-    cls = Class::New<GrowableObjectArray, RTN::GrowableObjectArray>(isolate);
+    cls = Class::New<GrowableObjectArray>(isolate);
     object_store->set_growable_object_array_class(cls);
 
-    cls = Class::New<LinkedHashMap, RTN::LinkedHashMap>(isolate);
+    cls = Class::New<LinkedHashMap>(isolate);
     object_store->set_linked_hash_map_class(cls);
 
-    cls = Class::New<Float32x4, RTN::Float32x4>(isolate);
+    cls = Class::New<Float32x4>(isolate);
     object_store->set_float32x4_class(cls);
 
-    cls = Class::New<Int32x4, RTN::Int32x4>(isolate);
+    cls = Class::New<Int32x4>(isolate);
     object_store->set_int32x4_class(cls);
 
-    cls = Class::New<Float64x2, RTN::Float64x2>(isolate);
+    cls = Class::New<Float64x2>(isolate);
     object_store->set_float64x2_class(cls);
 
 #define REGISTER_TYPED_DATA_CLASS(clazz)                                       \
@@ -2339,45 +2307,44 @@ RawError* Object::Init(Isolate* isolate,
     CLASS_LIST_TYPED_DATA(REGISTER_EXT_TYPED_DATA_CLASS);
 #undef REGISTER_EXT_TYPED_DATA_CLASS
 
-    cls = Class::New<Instance, RTN::Instance>(kFfiNativeTypeCid, isolate);
+    cls = Class::New<Instance>(kFfiNativeTypeCid, isolate);
     object_store->set_ffi_native_type_class(cls);
 
 #define REGISTER_FFI_CLASS(clazz)                                              \
-  cls = Class::New<Instance, RTN::Instance>(kFfi##clazz##Cid, isolate);
+  cls = Class::New<Instance>(kFfi##clazz##Cid, isolate);
     CLASS_LIST_FFI_TYPE_MARKER(REGISTER_FFI_CLASS);
 #undef REGISTER_FFI_CLASS
 
 #define REGISTER_WASM_CLASS(clazz)                                             \
-  cls = Class::New<Instance, RTN::Instance>(k##clazz##Cid, isolate);
+  cls = Class::New<Instance>(k##clazz##Cid, isolate);
     CLASS_LIST_WASM(REGISTER_WASM_CLASS);
 #undef REGISTER_WASM_CLASS
 
-    cls = Class::New<Instance, RTN::Instance>(kFfiNativeFunctionCid, isolate);
+    cls = Class::New<Instance>(kFfiNativeFunctionCid, isolate);
 
     cls = Class::NewPointerClass(kFfiPointerCid, isolate);
     object_store->set_ffi_pointer_class(cls);
 
-    cls = Class::New<DynamicLibrary, RTN::DynamicLibrary>(kFfiDynamicLibraryCid,
-                                                          isolate);
+    cls = Class::New<DynamicLibrary>(kFfiDynamicLibraryCid, isolate);
 
-    cls = Class::New<Instance, RTN::Instance>(kByteBufferCid, isolate,
-                                              /*register_isolate=*/false);
-    cls.set_instance_size_in_words(0, 0);
+    cls = Class::New<Instance>(kByteBufferCid, isolate,
+                               /*register_isolate=*/false);
+    cls.set_instance_size_in_words(0);
     isolate->RegisterClass(cls);
 
-    cls = Class::New<Integer, RTN::Integer>(isolate);
+    cls = Class::New<Integer>(isolate);
     object_store->set_integer_implementation_class(cls);
 
-    cls = Class::New<Smi, RTN::Smi>(isolate);
+    cls = Class::New<Smi>(isolate);
     object_store->set_smi_class(cls);
 
-    cls = Class::New<Mint, RTN::Mint>(isolate);
+    cls = Class::New<Mint>(isolate);
     object_store->set_mint_class(cls);
 
-    cls = Class::New<Double, RTN::Double>(isolate);
+    cls = Class::New<Double>(isolate);
     object_store->set_double_class(cls);
 
-    cls = Class::New<Closure, RTN::Closure>(isolate);
+    cls = Class::New<Closure>(isolate);
     object_store->set_closure_class(cls);
 
     cls = Class::NewStringClass(kOneByteStringCid, isolate);
@@ -2392,27 +2359,26 @@ RawError* Object::Init(Isolate* isolate,
     cls = Class::NewStringClass(kExternalTwoByteStringCid, isolate);
     object_store->set_external_two_byte_string_class(cls);
 
-    cls = Class::New<Bool, RTN::Bool>(isolate);
+    cls = Class::New<Bool>(isolate);
     object_store->set_bool_class(cls);
 
-    cls = Class::New<Instance, RTN::Instance>(kNullCid, isolate);
+    cls = Class::New<Instance>(kNullCid, isolate);
     object_store->set_null_class(cls);
 
-    cls = Class::New<Capability, RTN::Capability>(isolate);
-    cls = Class::New<ReceivePort, RTN::ReceivePort>(isolate);
-    cls = Class::New<SendPort, RTN::SendPort>(isolate);
-    cls = Class::New<StackTrace, RTN::StackTrace>(isolate);
-    cls = Class::New<RegExp, RTN::RegExp>(isolate);
-    cls = Class::New<Number, RTN::Number>(isolate);
+    cls = Class::New<Capability>(isolate);
+    cls = Class::New<ReceivePort>(isolate);
+    cls = Class::New<SendPort>(isolate);
+    cls = Class::New<StackTrace>(isolate);
+    cls = Class::New<RegExp>(isolate);
+    cls = Class::New<Number>(isolate);
 
-    cls = Class::New<WeakProperty, RTN::WeakProperty>(isolate);
+    cls = Class::New<WeakProperty>(isolate);
     object_store->set_weak_property_class(cls);
 
-    cls = Class::New<MirrorReference, RTN::MirrorReference>(isolate);
-    cls = Class::New<UserTag, RTN::UserTag>(isolate);
+    cls = Class::New<MirrorReference>(isolate);
+    cls = Class::New<UserTag>(isolate);
 
-    cls =
-        Class::New<TransferableTypedData, RTN::TransferableTypedData>(isolate);
+    cls = Class::New<TransferableTypedData>(isolate);
   }
   return Error::null();
 }
@@ -2681,7 +2647,7 @@ RawAbstractType* Class::RareType() const {
   return ClassFinalizer::FinalizeType(*this, type);
 }
 
-template <class FakeObject, class TargetFakeObject>
+template <class FakeObject>
 RawClass* Class::New(Isolate* isolate, bool register_class) {
   ASSERT(Object::class_class() != Class::null());
   Class& result = Class::Handle();
@@ -2694,15 +2660,9 @@ RawClass* Class::New(Isolate* isolate, bool register_class) {
   Object::VerifyBuiltinVtable<FakeObject>(FakeObject::kClassId);
   result.set_token_pos(TokenPosition::kNoSource);
   result.set_end_token_pos(TokenPosition::kNoSource);
-  result.set_instance_size(FakeObject::InstanceSize(),
-                           compiler::target::RoundedAllocationSize(
-                               TargetFakeObject::InstanceSize()));
-  result.set_type_arguments_field_offset_in_words(kNoTypeArguments,
-                                                  RTN::Class::kNoTypeArguments);
-  const intptr_t host_next_field_offset = FakeObject::NextFieldOffset();
-  const intptr_t target_next_field_offset = TargetFakeObject::NextFieldOffset();
-  result.set_next_field_offset(host_next_field_offset,
-                               target_next_field_offset);
+  result.set_instance_size(FakeObject::InstanceSize());
+  result.set_type_arguments_field_offset_in_words(kNoTypeArguments);
+  result.set_next_field_offset(FakeObject::NextFieldOffset());
   COMPILE_ASSERT((FakeObject::kClassId != kInstanceCid));
   result.set_id(FakeObject::kClassId);
   result.set_num_type_arguments(0);
@@ -2767,7 +2727,7 @@ RawArray* Class::OffsetToFieldMap(bool original_classes) const {
   Array& array = Array::Handle(raw_ptr()->offset_in_words_to_field_);
   if (array.IsNull()) {
     ASSERT(is_finalized());
-    const intptr_t length = raw_ptr()->host_instance_size_in_words_;
+    const intptr_t length = raw_ptr()->instance_size_in_words_;
     array = Array::New(length, Heap::kOld);
     Class& cls = Class::Handle(this->raw());
     Array& fields = Array::Handle();
@@ -2777,7 +2737,7 @@ RawArray* Class::OffsetToFieldMap(bool original_classes) const {
       for (intptr_t i = 0; i < fields.Length(); ++i) {
         f ^= fields.At(i);
         if (f.is_instance()) {
-          array.SetAt(f.HostOffset() >> kWordSizeLog2, f);
+          array.SetAt(f.Offset() >> kWordSizeLog2, f);
         }
       }
       cls = cls.SuperClass(original_classes);
@@ -3160,127 +3120,51 @@ RawTypeParameter* Class::LookupTypeParameter(const String& type_name) const {
   return TypeParameter::null();
 }
 
-UnboxedFieldBitmap Class::CalculateFieldOffsets() const {
+void Class::CalculateFieldOffsets() const {
   Array& flds = Array::Handle(fields());
   const Class& super = Class::Handle(SuperClass());
-  intptr_t host_offset = 0;
-  UnboxedFieldBitmap host_bitmap{};
-  // Target offsets might differ if the word size are different
-  intptr_t target_offset = 0;
-  intptr_t host_type_args_field_offset = kNoTypeArguments;
-  intptr_t target_type_args_field_offset = RTN::Class::kNoTypeArguments;
+  intptr_t offset = 0;
+  intptr_t type_args_field_offset = kNoTypeArguments;
   if (super.IsNull()) {
-    host_offset = Instance::NextFieldOffset();
-    target_offset = RTN::Instance::NextFieldOffset();
-    ASSERT(host_offset > 0);
-    ASSERT(target_offset > 0);
+    offset = Instance::NextFieldOffset();
+    ASSERT(offset > 0);
   } else {
     ASSERT(super.is_finalized() || super.is_prefinalized());
-    host_type_args_field_offset = super.host_type_arguments_field_offset();
-    target_type_args_field_offset = super.target_type_arguments_field_offset();
-    host_offset = super.host_next_field_offset();
-    ASSERT(host_offset > 0);
-    target_offset = super.target_next_field_offset();
-    ASSERT(target_offset > 0);
+    type_args_field_offset = super.type_arguments_field_offset();
+    offset = super.next_field_offset();
+    ASSERT(offset > 0);
     // We should never call CalculateFieldOffsets for native wrapper
     // classes, assert this.
     ASSERT(num_native_fields() == 0);
     set_num_native_fields(super.num_native_fields());
-
-    if (FLAG_precompiled_mode) {
-      host_bitmap =
-          Isolate::Current()->shared_class_table()->GetUnboxedFieldsMapAt(
-              super.id());
-    }
   }
   // If the super class is parameterized, use the same type_arguments field,
   // otherwise, if this class is the first in the super chain to be
   // parameterized, introduce a new type_arguments field.
-  if (host_type_args_field_offset == kNoTypeArguments) {
-    ASSERT(target_type_args_field_offset == RTN::Class::kNoTypeArguments);
+  if (type_args_field_offset == kNoTypeArguments) {
     const TypeArguments& type_params = TypeArguments::Handle(type_parameters());
     if (!type_params.IsNull()) {
       ASSERT(type_params.Length() > 0);
       // The instance needs a type_arguments field.
-      host_type_args_field_offset = host_offset;
-      target_type_args_field_offset = target_offset;
-      host_offset += kWordSize;
-      target_offset += compiler::target::kWordSize;
+      type_args_field_offset = offset;
+      offset += kWordSize;
     }
-  } else {
-    ASSERT(target_type_args_field_offset != RTN::Class::kNoTypeArguments);
   }
-
-  set_type_arguments_field_offset(host_type_args_field_offset,
-                                  target_type_args_field_offset);
-  ASSERT(host_offset > 0);
-  ASSERT(target_offset > 0);
+  set_type_arguments_field_offset(type_args_field_offset);
+  ASSERT(offset > 0);
   Field& field = Field::Handle();
-  const intptr_t len = flds.Length();
+  intptr_t len = flds.Length();
   for (intptr_t i = 0; i < len; i++) {
     field ^= flds.At(i);
     // Offset is computed only for instance fields.
     if (!field.is_static()) {
-      ASSERT(field.HostOffset() == 0);
-      ASSERT(field.TargetOffset() == 0);
-      field.SetOffset(host_offset, target_offset);
-
-      if (FLAG_precompiled_mode && field.is_unboxing_candidate()) {
-        intptr_t field_size;
-        switch (field.guarded_cid()) {
-          case kDoubleCid:
-            field_size = sizeof(RawDouble::value_);
-            break;
-          case kFloat32x4Cid:
-            field_size = sizeof(RawFloat32x4::value_);
-            break;
-          case kFloat64x2Cid:
-            field_size = sizeof(RawFloat64x2::value_);
-            break;
-          default:
-            UNREACHABLE();
-            field_size = 0;
-            break;
-        }
-
-        const intptr_t host_num_words = field_size / kWordSize;
-        const intptr_t host_next_offset = host_offset + field_size;
-        const intptr_t host_next_position = host_next_offset / kWordSize;
-
-        const intptr_t target_next_offset = target_offset + field_size;
-        const intptr_t target_next_position =
-            target_next_offset / compiler::target::kWordSize;
-
-        // The bitmap has fixed length. Checks if the offset position is smaller
-        // than its length. If it is not, than the field should be boxed
-        if (host_next_position <= UnboxedFieldBitmap::Length() &&
-            target_next_position <= UnboxedFieldBitmap::Length()) {
-          for (intptr_t j = 0; j < host_num_words; j++) {
-            // Activate the respective bit in the bitmap, indicating that the
-            // content is not a pointer
-            host_bitmap.Set(host_offset / kWordSize);
-            host_offset += kWordSize;
-          }
-
-          ASSERT(host_offset == host_next_offset);
-          target_offset = target_next_offset;
-        } else {
-          // Make the field boxed
-          field.set_is_unboxing_candidate(false);
-          host_offset += kWordSize;
-          target_offset += compiler::target::kWordSize;
-        }
-      } else {
-        host_offset += kWordSize;
-        target_offset += compiler::target::kWordSize;
-      }
+      ASSERT(field.Offset() == 0);
+      field.SetOffset(offset);
+      offset += kWordSize;
     }
   }
-  set_instance_size(RoundedAllocationSize(host_offset),
-                    compiler::target::RoundedAllocationSize(target_offset));
-  set_next_field_offset(host_offset, target_offset);
-
-  return host_bitmap;
+  set_instance_size(RoundedAllocationSize(offset));
+  set_next_field_offset(offset);
 }
 
 void Class::AddInvocationDispatcher(const String& target_name,
@@ -3642,15 +3526,11 @@ void Class::Finalize() const {
   // Prefinalized classes have a VM internal representation and no Dart fields.
   // Their instance size  is precomputed and field offsets are known.
   if (!is_prefinalized()) {
-    // Compute offsets of instance fields, instance size and bitmap for unboxed
-    // fields.
-    const auto host_bitmap = CalculateFieldOffsets();
+    // Compute offsets of instance fields and instance size.
+    CalculateFieldOffsets();
     if (raw() == isolate->class_table()->At(id())) {
       // Sets the new size in the class table.
       isolate->class_table()->SetAt(id(), raw());
-      if (FLAG_precompiled_mode) {
-        isolate->shared_class_table()->SetUnboxedFieldsMapAt(id(), host_bitmap);
-      }
     }
   }
   set_is_finalized();
@@ -4160,7 +4040,7 @@ bool Class::InjectCIDFields() const {
   return true;
 }
 
-template <class FakeInstance, class TargetFakeInstance>
+template <class FakeInstance>
 RawClass* Class::NewCommon(intptr_t index) {
   ASSERT(Object::class_class() != Class::null());
   Class& result = Class::Handle();
@@ -4175,17 +4055,9 @@ RawClass* Class::NewCommon(intptr_t index) {
                                                                  : index);
   result.set_token_pos(TokenPosition::kNoSource);
   result.set_end_token_pos(TokenPosition::kNoSource);
-  const intptr_t host_instance_size = FakeInstance::InstanceSize();
-  const intptr_t target_instance_size = compiler::target::RoundedAllocationSize(
-      TargetFakeInstance::InstanceSize());
-  result.set_instance_size(host_instance_size, target_instance_size);
-  result.set_type_arguments_field_offset_in_words(kNoTypeArguments,
-                                                  RTN::Class::kNoTypeArguments);
-  const intptr_t host_next_field_offset = FakeInstance::NextFieldOffset();
-  const intptr_t target_next_field_offset =
-      TargetFakeInstance::NextFieldOffset();
-  result.set_next_field_offset(host_next_field_offset,
-                               target_next_field_offset);
+  result.set_instance_size(FakeInstance::InstanceSize());
+  result.set_type_arguments_field_offset_in_words(kNoTypeArguments);
+  result.set_next_field_offset(FakeInstance::NextFieldOffset());
   result.set_id(index);
   result.set_num_type_arguments(kUnknownNumTypeArguments);
   result.set_num_native_fields(0);
@@ -4196,13 +4068,12 @@ RawClass* Class::NewCommon(intptr_t index) {
   return result.raw();
 }
 
-template <class FakeInstance, class TargetFakeInstance>
+template <class FakeInstance>
 RawClass* Class::New(intptr_t index,
                      Isolate* isolate,
                      bool register_class,
                      bool is_abstract) {
-  Class& result =
-      Class::Handle(NewCommon<FakeInstance, TargetFakeInstance>(index));
+  Class& result = Class::Handle(NewCommon<FakeInstance>(index));
   if (is_abstract) {
     result.set_is_abstract();
   }
@@ -4217,8 +4088,7 @@ RawClass* Class::New(const Library& lib,
                      const Script& script,
                      TokenPosition token_pos,
                      bool register_class) {
-  Class& result =
-      Class::Handle(NewCommon<Instance, RTN::Instance>(kIllegalCid));
+  Class& result = Class::Handle(NewCommon<Instance>(kIllegalCid));
   result.set_library(lib);
   result.set_name(name);
   result.set_script(script);
@@ -4227,7 +4097,7 @@ RawClass* Class::New(const Library& lib,
   // The size gets initialized to 0. Once the class gets finalized the class
   // finalizer will set the correct size.
   ASSERT(!result.is_finalized() && !result.is_prefinalized());
-  result.set_instance_size_in_words(0, 0);
+  result.set_instance_size_in_words(0);
 
   if (register_class) {
     Isolate::Current()->RegisterClass(result);
@@ -4236,7 +4106,7 @@ RawClass* Class::New(const Library& lib,
 }
 
 RawClass* Class::NewInstanceClass() {
-  return Class::New<Instance, RTN::Instance>(kIllegalCid, Isolate::Current());
+  return Class::New<Instance>(kIllegalCid, Isolate::Current());
 }
 
 RawClass* Class::NewNativeWrapper(const Library& library,
@@ -4251,13 +4121,9 @@ RawClass* Class::NewNativeWrapper(const Library& library,
     cls.set_super_type(Type::Handle(Type::ObjectType()));
     // Compute instance size. First word contains a pointer to a properly
     // sized typed array once the first native field has been set.
-    const intptr_t host_instance_size = sizeof(RawInstance) + kWordSize;
-    const intptr_t target_instance_size =
-        sizeof(RawInstance) + compiler::target::kWordSize;
-    cls.set_instance_size(
-        RoundedAllocationSize(host_instance_size),
-        compiler::target::RoundedAllocationSize(target_instance_size));
-    cls.set_next_field_offset(host_instance_size, target_instance_size);
+    intptr_t instance_size = sizeof(RawInstance) + kWordSize;
+    cls.set_instance_size(RoundedAllocationSize(instance_size));
+    cls.set_next_field_offset(instance_size);
     cls.set_num_native_fields(field_count);
     cls.set_is_finalized();
     cls.set_is_declaration_loaded();
@@ -4271,33 +4137,21 @@ RawClass* Class::NewNativeWrapper(const Library& library,
 }
 
 RawClass* Class::NewStringClass(intptr_t class_id, Isolate* isolate) {
-  intptr_t host_instance_size, target_instance_size;
+  intptr_t instance_size;
   if (class_id == kOneByteStringCid) {
-    host_instance_size = OneByteString::InstanceSize();
-    target_instance_size = compiler::target::RoundedAllocationSize(
-        RTN::OneByteString::InstanceSize());
+    instance_size = OneByteString::InstanceSize();
   } else if (class_id == kTwoByteStringCid) {
-    host_instance_size = TwoByteString::InstanceSize();
-    target_instance_size = compiler::target::RoundedAllocationSize(
-        RTN::TwoByteString::InstanceSize());
+    instance_size = TwoByteString::InstanceSize();
   } else if (class_id == kExternalOneByteStringCid) {
-    host_instance_size = ExternalOneByteString::InstanceSize();
-    target_instance_size = compiler::target::RoundedAllocationSize(
-        RTN::ExternalOneByteString::InstanceSize());
+    instance_size = ExternalOneByteString::InstanceSize();
   } else {
     ASSERT(class_id == kExternalTwoByteStringCid);
-    host_instance_size = ExternalTwoByteString::InstanceSize();
-    target_instance_size = compiler::target::RoundedAllocationSize(
-        RTN::ExternalTwoByteString::InstanceSize());
+    instance_size = ExternalTwoByteString::InstanceSize();
   }
-  Class& result = Class::Handle(
-      New<String, RTN::String>(class_id, isolate, /*register_class=*/false));
-  result.set_instance_size(host_instance_size, target_instance_size);
-
-  const intptr_t host_next_field_offset = String::NextFieldOffset();
-  const intptr_t target_next_field_offset = RTN::String::NextFieldOffset();
-  result.set_next_field_offset(host_next_field_offset,
-                               target_next_field_offset);
+  Class& result =
+      Class::Handle(New<String>(class_id, isolate, /*register_class=*/false));
+  result.set_instance_size(instance_size);
+  result.set_next_field_offset(String::NextFieldOffset());
   result.set_is_prefinalized();
   isolate->RegisterClass(result);
   return result.raw();
@@ -4305,17 +4159,11 @@ RawClass* Class::NewStringClass(intptr_t class_id, Isolate* isolate) {
 
 RawClass* Class::NewTypedDataClass(intptr_t class_id, Isolate* isolate) {
   ASSERT(RawObject::IsTypedDataClassId(class_id));
-  const intptr_t host_instance_size = TypedData::InstanceSize();
-  const intptr_t target_instance_size =
-      compiler::target::RoundedAllocationSize(RTN::TypedData::InstanceSize());
-  Class& result = Class::Handle(New<TypedData, RTN::TypedData>(
-      class_id, isolate, /*register_class=*/false));
-  result.set_instance_size(host_instance_size, target_instance_size);
-
-  const intptr_t host_next_field_offset = TypedData::NextFieldOffset();
-  const intptr_t target_next_field_offset = RTN::TypedData::NextFieldOffset();
-  result.set_next_field_offset(host_next_field_offset,
-                               target_next_field_offset);
+  intptr_t instance_size = TypedData::InstanceSize();
+  Class& result = Class::Handle(
+      New<TypedData>(class_id, isolate, /*register_class=*/false));
+  result.set_instance_size(instance_size);
+  result.set_next_field_offset(TypedData::NextFieldOffset());
   result.set_is_prefinalized();
   isolate->RegisterClass(result);
   return result.raw();
@@ -4323,18 +4171,11 @@ RawClass* Class::NewTypedDataClass(intptr_t class_id, Isolate* isolate) {
 
 RawClass* Class::NewTypedDataViewClass(intptr_t class_id, Isolate* isolate) {
   ASSERT(RawObject::IsTypedDataViewClassId(class_id));
-  const intptr_t host_instance_size = TypedDataView::InstanceSize();
-  const intptr_t target_instance_size = compiler::target::RoundedAllocationSize(
-      RTN::TypedDataView::InstanceSize());
-  Class& result = Class::Handle(New<TypedDataView, RTN::TypedDataView>(
-      class_id, isolate, /*register_class=*/false));
-  result.set_instance_size(host_instance_size, target_instance_size);
-
-  const intptr_t host_next_field_offset = TypedDataView::NextFieldOffset();
-  const intptr_t target_next_field_offset =
-      RTN::TypedDataView::NextFieldOffset();
-  result.set_next_field_offset(host_next_field_offset,
-                               target_next_field_offset);
+  const intptr_t instance_size = TypedDataView::InstanceSize();
+  Class& result = Class::Handle(
+      New<TypedDataView>(class_id, isolate, /*register_class=*/false));
+  result.set_instance_size(instance_size);
+  result.set_next_field_offset(TypedDataView::NextFieldOffset());
   result.set_is_prefinalized();
   isolate->RegisterClass(result);
   return result.raw();
@@ -4343,18 +4184,11 @@ RawClass* Class::NewTypedDataViewClass(intptr_t class_id, Isolate* isolate) {
 RawClass* Class::NewExternalTypedDataClass(intptr_t class_id,
                                            Isolate* isolate) {
   ASSERT(RawObject::IsExternalTypedDataClassId(class_id));
-  const intptr_t host_instance_size = ExternalTypedData::InstanceSize();
-  const intptr_t target_instance_size = compiler::target::RoundedAllocationSize(
-      RTN::ExternalTypedData::InstanceSize());
-  Class& result = Class::Handle(New<ExternalTypedData, RTN::ExternalTypedData>(
-      class_id, isolate, /*register_class=*/false));
-
-  const intptr_t host_next_field_offset = ExternalTypedData::NextFieldOffset();
-  const intptr_t target_next_field_offset =
-      RTN::ExternalTypedData::NextFieldOffset();
-  result.set_instance_size(host_instance_size, target_instance_size);
-  result.set_next_field_offset(host_next_field_offset,
-                               target_next_field_offset);
+  intptr_t instance_size = ExternalTypedData::InstanceSize();
+  Class& result = Class::Handle(
+      New<ExternalTypedData>(class_id, isolate, /*register_class=*/false));
+  result.set_instance_size(instance_size);
+  result.set_next_field_offset(ExternalTypedData::NextFieldOffset());
   result.set_is_prefinalized();
   isolate->RegisterClass(result);
   return result.raw();
@@ -4362,20 +4196,12 @@ RawClass* Class::NewExternalTypedDataClass(intptr_t class_id,
 
 RawClass* Class::NewPointerClass(intptr_t class_id, Isolate* isolate) {
   ASSERT(RawObject::IsFfiPointerClassId(class_id));
-  intptr_t host_instance_size = Pointer::InstanceSize();
-  intptr_t target_instance_size =
-      compiler::target::RoundedAllocationSize(RTN::Pointer::InstanceSize());
-  Class& result = Class::Handle(
-      New<Pointer, RTN::Pointer>(class_id, isolate, /*register_class=*/false));
-  result.set_instance_size(host_instance_size, target_instance_size);
-  result.set_type_arguments_field_offset(Pointer::type_arguments_offset(),
-                                         RTN::Pointer::type_arguments_offset());
-
-  const intptr_t host_next_field_offset = Pointer::NextFieldOffset();
-  const intptr_t target_next_field_offset = RTN::Pointer::NextFieldOffset();
-
-  result.set_next_field_offset(host_next_field_offset,
-                               target_next_field_offset);
+  intptr_t instance_size = Pointer::InstanceSize();
+  Class& result =
+      Class::Handle(New<Pointer>(class_id, isolate, /*register_class=*/false));
+  result.set_instance_size(instance_size);
+  result.set_type_arguments_field_offset(Pointer::type_arguments_offset());
+  result.set_next_field_offset(Pointer::NextFieldOffset());
   result.set_is_prefinalized();
   isolate->RegisterClass(result);
   return result.raw();
@@ -8967,6 +8793,12 @@ RawField* Field::Original() const {
   }
 }
 
+void Instance::SetField(const Field& field, const Object& value) const {
+  field.RecordStore(value);
+  const Object* stored_value = field.CloneForUnboxed(value);
+  StorePointer(FieldAddr(field), stored_value->raw());
+}
+
 const Object* Field::CloneForUnboxed(const Object& value) const {
   if (FLAG_unbox_numeric_fields && is_unboxing_candidate() && !is_nullable()) {
     switch (guarded_cid()) {
@@ -9161,7 +8993,7 @@ void Field::InitializeNew(const Field& result,
   result.set_name(name);
   result.set_is_static(is_static);
   if (!is_static) {
-    result.SetOffset(0, 0);
+    result.SetOffset(0);
   }
   result.set_is_final(is_final);
   result.set_is_const(is_const);
@@ -9173,12 +9005,7 @@ void Field::InitializeNew(const Field& result,
   result.set_end_token_pos(end_token_pos);
   result.set_has_nontrivial_initializer(false);
   result.set_has_initializer(false);
-  if (FLAG_precompiled_mode) {
-    // May be updated by KernelLoader::ReadInferredType
-    result.set_is_unboxing_candidate(false);
-  } else {
-    result.set_is_unboxing_candidate(!is_final && !is_late && !is_static);
-  }
+  result.set_is_unboxing_candidate(!is_final && !is_late && !is_static);
   result.set_initializer_changed_after_initialization(false);
   NOT_IN_PRECOMPILED(result.set_is_declared_in_bytecode(false));
   NOT_IN_PRECOMPILED(result.set_binary_declaration_offset(0));
@@ -9765,7 +9592,7 @@ void Field::SetStaticValue(const Instance& value,
 }
 
 static StaticTypeExactnessState TrivialTypeExactnessFor(const Class& cls) {
-  const intptr_t type_arguments_offset = cls.host_type_arguments_field_offset();
+  const intptr_t type_arguments_offset = cls.type_arguments_field_offset();
   ASSERT(type_arguments_offset != Class::kNoTypeArguments);
   if (StaticTypeExactnessState::CanRepresentAsTriviallyExact(
           type_arguments_offset / kWordSize)) {
@@ -17065,19 +16892,10 @@ uint32_t Instance::CanonicalizeHash() const {
   hash = instance_size / kWordSize;
   uword this_addr = reinterpret_cast<uword>(this->raw_ptr());
   Instance& member = Instance::Handle();
-  const auto unboxed_fields_bitmap =
-      thread->isolate()->shared_class_table()->GetUnboxedFieldsMapAt(
-          GetClassId());
-
   for (intptr_t offset = Instance::NextFieldOffset(); offset < instance_size;
        offset += kWordSize) {
-    if (unboxed_fields_bitmap.Get(offset / kWordSize)) {
-      hash =
-          CombineHashes(hash, *reinterpret_cast<intptr_t*>(this_addr + offset));
-    } else {
-      member ^= *reinterpret_cast<RawObject**>(this_addr + offset);
-      hash = CombineHashes(hash, member.CanonicalizeHash());
-    }
+    member ^= *reinterpret_cast<RawObject**>(this_addr + offset);
+    hash = CombineHashes(hash, member.CanonicalizeHash());
   }
   hash = FinalizeHash(hash, String::kHashBits);
   thread->heap()->SetCanonicalHash(raw(), hash);
@@ -17109,22 +16927,15 @@ bool Instance::CheckAndCanonicalizeFields(Thread* thread,
                                           const char** error_str) const {
   ASSERT(error_str != NULL);
   ASSERT(*error_str == NULL);
-  const intptr_t class_id = GetClassId();
-  if (class_id >= kNumPredefinedCids) {
+  if (GetClassId() >= kNumPredefinedCids) {
     // Iterate over all fields, canonicalize numbers and strings, expect all
     // other instances to be canonical otherwise report error (return false).
     Zone* zone = thread->zone();
     Object& obj = Object::Handle(zone);
     const intptr_t instance_size = SizeFromClass();
     ASSERT(instance_size != 0);
-    const auto unboxed_fields_bitmap =
-        thread->isolate()->shared_class_table()->GetUnboxedFieldsMapAt(
-            GetClassId());
     for (intptr_t offset = Instance::NextFieldOffset(); offset < instance_size;
          offset += kWordSize) {
-      if (unboxed_fields_bitmap.Get(offset / kWordSize)) {
-        continue;
-      }
       obj = *this->FieldAddrAtOffset(offset);
       if (obj.IsInstance() && !obj.IsSmi() && !obj.IsCanonical()) {
         if (obj.IsNumber() || obj.IsString()) {
@@ -17203,53 +17014,6 @@ bool Instance::CheckIsCanonical(Thread* thread) const {
 }
 #endif  // DEBUG
 
-RawObject* Instance::GetField(const Field& field) const {
-  if (FLAG_precompiled_mode && field.is_unboxing_candidate()) {
-    switch (field.guarded_cid()) {
-      case kDoubleCid:
-        return Double::New(
-            LoadNonPointer(reinterpret_cast<double_t*>(FieldAddr(field))));
-      case kFloat32x4Cid:
-        return Float32x4::New(
-            *reinterpret_cast<simd128_value_t*>(FieldAddr(field)));
-      case kFloat64x2Cid:
-        return Float64x2::New(
-            *reinterpret_cast<simd128_value_t*>(FieldAddr(field)));
-      default:
-        UNREACHABLE();
-        return nullptr;
-    }
-  } else {
-    return *FieldAddr(field);
-  }
-}
-
-void Instance::SetField(const Field& field, const Object& value) const {
-  if (FLAG_precompiled_mode && field.is_unboxing_candidate()) {
-    switch (field.guarded_cid()) {
-      case kDoubleCid:
-        StoreNonPointer(reinterpret_cast<double_t*>(FieldAddr(field)),
-                        Double::Cast(value).value());
-        break;
-      case kFloat32x4Cid:
-        StoreNonPointer(reinterpret_cast<simd128_value_t*>(FieldAddr(field)),
-                        Float32x4::Cast(value).value());
-        break;
-      case kFloat64x2Cid:
-        StoreNonPointer(reinterpret_cast<simd128_value_t*>(FieldAddr(field)),
-                        Float64x2::Cast(value).value());
-        break;
-      default:
-        UNREACHABLE();
-        break;
-    }
-  } else {
-    field.RecordStore(value);
-    const Object* stored_value = field.CloneForUnboxed(value);
-    StorePointer(FieldAddr(field), stored_value->raw());
-  }
-}
-
 RawAbstractType* Instance::GetType(Heap::Space space) const {
   if (IsNull()) {
     return Type::NullType();
@@ -17294,7 +17058,7 @@ RawAbstractType* Instance::GetType(Heap::Space space) const {
 RawTypeArguments* Instance::GetTypeArguments() const {
   ASSERT(!IsType());
   const Class& cls = Class::Handle(clazz());
-  intptr_t field_offset = cls.host_type_arguments_field_offset();
+  intptr_t field_offset = cls.type_arguments_field_offset();
   ASSERT(field_offset != Class::kNoTypeArguments);
   TypeArguments& type_arguments = TypeArguments::Handle();
   type_arguments ^= *FieldAddrAtOffset(field_offset);
@@ -17305,7 +17069,7 @@ void Instance::SetTypeArguments(const TypeArguments& value) const {
   ASSERT(!IsType());
   ASSERT(value.IsNull() || value.IsCanonical());
   const Class& cls = Class::Handle(clazz());
-  intptr_t field_offset = cls.host_type_arguments_field_offset();
+  intptr_t field_offset = cls.type_arguments_field_offset();
   ASSERT(field_offset != Class::kNoTypeArguments);
   SetFieldAtOffset(field_offset, value);
 }
@@ -17672,7 +17436,7 @@ RawInstance* Instance::New(const Class& cls, Heap::Space space) {
   if (cls.EnsureIsFinalized(thread) != Error::null()) {
     return Instance::null();
   }
-  intptr_t instance_size = cls.host_instance_size();
+  intptr_t instance_size = cls.instance_size();
   ASSERT(instance_size > 0);
   RawObject* raw = Object::Allocate(cls.id(), instance_size, space);
   return reinterpret_cast<RawInstance*>(raw);
@@ -17691,7 +17455,7 @@ bool Instance::IsValidFieldOffset(intptr_t offset) const {
   REUSABLE_CLASS_HANDLESCOPE(thread);
   Class& cls = thread->ClassHandle();
   cls = clazz();
-  return (offset >= 0 && offset <= (cls.host_instance_size() - kWordSize));
+  return (offset >= 0 && offset <= (cls.instance_size() - kWordSize));
 }
 
 intptr_t Instance::ElementSizeFor(intptr_t cid) {
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 44120f9f402eb..2759213139093 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -266,15 +266,6 @@ class ZoneTextBuffer;
 #define MINT_OBJECT_IMPLEMENTATION(object, rettype, super)                     \
   FINAL_HEAP_OBJECT_IMPLEMENTATION_HELPER(object, rettype, super)
 
-// In precompiled runtime, there is no access to runtime_api.cc since host
-// and target are the same. In those cases, the namespace dart is used to refer
-// to the target namespace
-#if defined(DART_PRECOMPILED_RUNTIME)
-namespace RTN = dart;
-#else
-namespace RTN = dart::compiler::target;
-#endif  //  defined(DART_PRECOMPILED_RUNTIME)
-
 class Object {
  public:
   using RawObjectType = RawObject;
@@ -894,88 +885,36 @@ class Class : public Object {
     kInvocationDispatcherEntrySize,
   };
 
-  intptr_t host_instance_size() const {
-    ASSERT(is_finalized() || is_prefinalized());
-    return (raw_ptr()->host_instance_size_in_words_ * kWordSize);
-  }
-  intptr_t target_instance_size() const {
+  intptr_t instance_size() const {
     ASSERT(is_finalized() || is_prefinalized());
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return (raw_ptr()->target_instance_size_in_words_ *
-            compiler::target::kWordSize);
-#else
-    return host_instance_size();
-#endif  // !defined(DART_PRECOMPILED_RUNTIME)
+    return (raw_ptr()->instance_size_in_words_ * kWordSize);
   }
-  static intptr_t host_instance_size(RawClass* clazz) {
-    return (clazz->ptr()->host_instance_size_in_words_ * kWordSize);
+  static intptr_t instance_size(RawClass* clazz) {
+    return (clazz->ptr()->instance_size_in_words_ * kWordSize);
   }
-  static intptr_t target_instance_size(RawClass* clazz) {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return (clazz->ptr()->target_instance_size_in_words_ *
-            compiler::target::kWordSize);
-#else
-    return host_instance_size(clazz);
-#endif  // !defined(DART_PRECOMPILED_RUNTIME)
-  }
-  void set_instance_size(intptr_t host_value_in_bytes,
-                         intptr_t target_value_in_bytes) const {
+  void set_instance_size(intptr_t value_in_bytes) const {
     ASSERT(kWordSize != 0);
-    set_instance_size_in_words(
-        host_value_in_bytes / kWordSize,
-        target_value_in_bytes / compiler::target::kWordSize);
-  }
-  void set_instance_size_in_words(intptr_t host_value,
-                                  intptr_t target_value) const {
-    ASSERT(Utils::IsAligned((host_value * kWordSize), kObjectAlignment));
-    StoreNonPointer(&raw_ptr()->host_instance_size_in_words_, host_value);
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    ASSERT(Utils::IsAligned((target_value * compiler::target::kWordSize),
-                            compiler::target::kObjectAlignment));
-    StoreNonPointer(&raw_ptr()->target_instance_size_in_words_, target_value);
-#else
-    ASSERT(host_value == target_value);
-#endif  // #!defined(DART_PRECOMPILED_RUNTIME)
+    set_instance_size_in_words(value_in_bytes / kWordSize);
+  }
+  void set_instance_size_in_words(intptr_t value) const {
+    ASSERT(Utils::IsAligned((value * kWordSize), kObjectAlignment));
+    StoreNonPointer(&raw_ptr()->instance_size_in_words_, value);
   }
 
-  intptr_t host_next_field_offset() const {
-    return raw_ptr()->host_next_field_offset_in_words_ * kWordSize;
+  intptr_t next_field_offset() const {
+    return raw_ptr()->next_field_offset_in_words_ * kWordSize;
   }
-  intptr_t target_next_field_offset() const {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return raw_ptr()->target_next_field_offset_in_words_ *
-           compiler::target::kWordSize;
-#else
-    return host_next_field_offset();
-#endif  // #!defined(DART_PRECOMPILED_RUNTIME)
-  }
-  void set_next_field_offset(intptr_t host_value_in_bytes,
-                             intptr_t target_value_in_bytes) const {
-    set_next_field_offset_in_words(
-        host_value_in_bytes / kWordSize,
-        target_value_in_bytes / compiler::target::kWordSize);
-  }
-  void set_next_field_offset_in_words(intptr_t host_value,
-                                      intptr_t target_value) const {
-    ASSERT((host_value == -1) ||
-           (Utils::IsAligned((host_value * kWordSize), kObjectAlignment) &&
-            (host_value == raw_ptr()->host_instance_size_in_words_)) ||
-           (!Utils::IsAligned((host_value * kWordSize), kObjectAlignment) &&
-            ((host_value + 1) == raw_ptr()->host_instance_size_in_words_)));
-    StoreNonPointer(&raw_ptr()->host_next_field_offset_in_words_, host_value);
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    ASSERT((target_value == -1) ||
-           (Utils::IsAligned((target_value * compiler::target::kWordSize),
-                             compiler::target::kObjectAlignment) &&
-            (target_value == raw_ptr()->target_instance_size_in_words_)) ||
-           (!Utils::IsAligned((target_value * compiler::target::kWordSize),
-                              compiler::target::kObjectAlignment) &&
-            ((target_value + 1) == raw_ptr()->target_instance_size_in_words_)));
-    StoreNonPointer(&raw_ptr()->target_next_field_offset_in_words_,
-                    target_value);
-#else
-    ASSERT(host_value == target_value);
-#endif  // #!defined(DART_PRECOMPILED_RUNTIME)
+  void set_next_field_offset(intptr_t value_in_bytes) const {
+    ASSERT(kWordSize != 0);
+    set_next_field_offset_in_words(value_in_bytes / kWordSize);
+  }
+  void set_next_field_offset_in_words(intptr_t value) const {
+    ASSERT((value == -1) ||
+           (Utils::IsAligned((value * kWordSize), kObjectAlignment) &&
+            (value == raw_ptr()->instance_size_in_words_)) ||
+           (!Utils::IsAligned((value * kWordSize), kObjectAlignment) &&
+            ((value + 1) == raw_ptr()->instance_size_in_words_)));
+    StoreNonPointer(&raw_ptr()->next_field_offset_in_words_, value);
   }
 
   static bool is_valid_id(intptr_t value) {
@@ -1074,64 +1013,28 @@ class Class : public Object {
 
   // If this class is parameterized, each instance has a type_arguments field.
   static const intptr_t kNoTypeArguments = -1;
-  intptr_t host_type_arguments_field_offset() const {
+  intptr_t type_arguments_field_offset() const {
     ASSERT(is_type_finalized() || is_prefinalized());
-    if (raw_ptr()->host_type_arguments_field_offset_in_words_ ==
-        kNoTypeArguments) {
+    if (raw_ptr()->type_arguments_field_offset_in_words_ == kNoTypeArguments) {
       return kNoTypeArguments;
     }
-    return raw_ptr()->host_type_arguments_field_offset_in_words_ * kWordSize;
+    return raw_ptr()->type_arguments_field_offset_in_words_ * kWordSize;
   }
-  intptr_t target_type_arguments_field_offset() const {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    ASSERT(is_type_finalized() || is_prefinalized());
-    if (raw_ptr()->target_type_arguments_field_offset_in_words_ ==
-        compiler::target::Class::kNoTypeArguments) {
-      return compiler::target::Class::kNoTypeArguments;
-    }
-    return raw_ptr()->target_type_arguments_field_offset_in_words_ *
-           compiler::target::kWordSize;
-#else
-    return host_type_arguments_field_offset();
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
-  }
-  void set_type_arguments_field_offset(intptr_t host_value_in_bytes,
-                                       intptr_t target_value_in_bytes) const {
-    intptr_t host_value, target_value;
-    if (host_value_in_bytes == kNoTypeArguments ||
-        target_value_in_bytes == RTN::Class::kNoTypeArguments) {
-      ASSERT(host_value_in_bytes == kNoTypeArguments &&
-             target_value_in_bytes == RTN::Class::kNoTypeArguments);
-      host_value = kNoTypeArguments;
-      target_value = RTN::Class::kNoTypeArguments;
+  void set_type_arguments_field_offset(intptr_t value_in_bytes) const {
+    intptr_t value;
+    if (value_in_bytes == kNoTypeArguments) {
+      value = kNoTypeArguments;
     } else {
-      ASSERT(kWordSize != 0 && compiler::target::kWordSize);
-      host_value = host_value_in_bytes / kWordSize;
-      target_value = target_value_in_bytes / compiler::target::kWordSize;
+      ASSERT(kWordSize != 0);
+      value = value_in_bytes / kWordSize;
     }
-    set_type_arguments_field_offset_in_words(host_value, target_value);
-  }
-  void set_type_arguments_field_offset_in_words(intptr_t host_value,
-                                                intptr_t target_value) const {
-    StoreNonPointer(&raw_ptr()->host_type_arguments_field_offset_in_words_,
-                    host_value);
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    StoreNonPointer(&raw_ptr()->target_type_arguments_field_offset_in_words_,
-                    target_value);
-#else
-    ASSERT(host_value == target_value);
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+    set_type_arguments_field_offset_in_words(value);
   }
-  static intptr_t host_type_arguments_field_offset_in_words_offset() {
-    return OFFSET_OF(RawClass, host_type_arguments_field_offset_in_words_);
+  void set_type_arguments_field_offset_in_words(intptr_t value) const {
+    StoreNonPointer(&raw_ptr()->type_arguments_field_offset_in_words_, value);
   }
-
-  static intptr_t target_type_arguments_field_offset_in_words_offset() {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return OFFSET_OF(RawClass, target_type_arguments_field_offset_in_words_);
-#else
-    return host_type_arguments_field_offset_in_words_offset();
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+  static intptr_t type_arguments_field_offset_in_words_offset() {
+    return OFFSET_OF(RawClass, type_arguments_field_offset_in_words_);
   }
 
   // The super type of this class, Object type if not explicitly specified.
@@ -1492,7 +1395,7 @@ class Class : public Object {
   RawError* EnsureIsFinalized(Thread* thread) const;
 
   // Allocate a class used for VM internal objects.
-  template <class FakeObject, class TargetFakeObject>
+  template <class FakeObject>
   static RawClass* New(Isolate* isolate, bool register_class = true);
 
   // Allocate instance classes.
@@ -1557,44 +1460,6 @@ class Class : public Object {
                                const Array& args_desc,
                                const Function& dispatcher) const;
 
-  static int32_t host_instance_size_in_words(const RawClass* cls) {
-    return cls->ptr()->host_instance_size_in_words_;
-  }
-
-  static int32_t target_instance_size_in_words(const RawClass* cls) {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return cls->ptr()->target_instance_size_in_words_;
-#else
-    return host_instance_size_in_words(cls);
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
-  }
-
-  static int32_t host_next_field_offset_in_words(const RawClass* cls) {
-    return cls->ptr()->host_next_field_offset_in_words_;
-  }
-
-  static int32_t target_next_field_offset_in_words(const RawClass* cls) {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return cls->ptr()->target_next_field_offset_in_words_;
-#else
-    return host_next_field_offset_in_words(cls);
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
-  }
-
-  static int32_t host_type_arguments_field_offset_in_words(
-      const RawClass* cls) {
-    return cls->ptr()->host_type_arguments_field_offset_in_words_;
-  }
-
-  static int32_t target_type_arguments_field_offset_in_words(
-      const RawClass* cls) {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return cls->ptr()->target_type_arguments_field_offset_in_words_;
-#else
-    return host_type_arguments_field_offset_in_words(cls);
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
-  }
-
  private:
   RawType* declaration_type() const { return raw_ptr()->declaration_type_; }
 
@@ -1609,7 +1474,7 @@ class Class : public Object {
   // Tells whether instances need morphing for reload.
   bool RequiresInstanceMorphing(const Class& replacement) const;
 
-  template <class FakeInstance, class TargetFakeInstance>
+  template <class FakeObject>
   static RawClass* NewCommon(intptr_t index);
 
   enum MemberKind {
@@ -1673,8 +1538,7 @@ class Class : public Object {
                                           const Array& args_desc,
                                           RawFunction::Kind kind) const;
 
-  // Returns the bitmap of unboxed fields
-  UnboxedFieldBitmap CalculateFieldOffsets() const;
+  void CalculateFieldOffsets() const;
 
   // functions_hash_table is in use iff there are at least this many functions.
   static const intptr_t kFunctionLookupHashTreshold = 16;
@@ -1712,7 +1576,7 @@ class Class : public Object {
                                       const String& name) const;
 
   // Allocate an instance class which has a VM implementation.
-  template <class FakeInstance, class TargetFakeInstance>
+  template <class FakeInstance>
   static RawClass* New(intptr_t id,
                        Isolate* isolate,
                        bool register_class = true,
@@ -3779,19 +3643,15 @@ class Field : public Object {
 
   intptr_t KernelDataProgramOffset() const;
 
+  inline intptr_t Offset() const;
   // Called during class finalization.
-  inline void SetOffset(intptr_t host_offset_in_bytes,
-                        intptr_t target_offset_in_bytes) const;
-
-  inline intptr_t HostOffset() const;
-
-  inline intptr_t TargetOffset() const;
+  inline void SetOffset(intptr_t offset_in_bytes) const;
 
   inline RawInstance* StaticValue() const;
   void SetStaticValue(const Instance& value,
                       bool save_initial_value = false) const;
 
-  intptr_t field_id() const { return raw_ptr()->host_offset_or_field_id_; }
+  intptr_t field_id() const { return raw_ptr()->offset_or_field_id_; }
   inline void set_field_id(intptr_t field_id) const;
 
 #ifndef DART_PRECOMPILED_RUNTIME
@@ -3888,14 +3748,6 @@ class Field : public Object {
     return OFFSET_OF(RawField, static_type_exactness_state_);
   }
 
-  static inline intptr_t TargetOffsetOf(const RawField* field) {
-#if !defined(DART_PRECOMPILED_RUNTIME)
-    return field->ptr()->target_offset_;
-#else
-    return field->ptr()->host_offset_or_field_id_;
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
-  }
-
   // Return class id that any non-null value read from this field is guaranteed
   // to have or kDynamicCid if such class id is not known.
   // Stores to this field must update this information hence the name.
@@ -6702,7 +6554,7 @@ class Instance : public Object {
     const Class& cls = Class::Handle(clazz());
     ASSERT(cls.is_finalized() || cls.is_prefinalized());
 #endif
-    return (clazz()->ptr()->host_instance_size_in_words_ * kWordSize);
+    return (clazz()->ptr()->instance_size_in_words_ * kWordSize);
   }
 
   // Returns Instance::null() if instance cannot be canonicalized.
@@ -6724,7 +6576,7 @@ class Instance : public Object {
   virtual bool CheckIsCanonical(Thread* thread) const;
 #endif  // DEBUG
 
-  RawObject* GetField(const Field& field) const;
+  RawObject* GetField(const Field& field) const { return *FieldAddr(field); }
 
   void SetField(const Field& field, const Object& value) const;
 
@@ -6861,7 +6713,7 @@ class Instance : public Object {
     return reinterpret_cast<RawObject**>(raw_value() - kHeapObjectTag + offset);
   }
   RawObject** FieldAddr(const Field& field) const {
-    return FieldAddrAtOffset(field.HostOffset());
+    return FieldAddrAtOffset(field.Offset());
   }
   RawObject** NativeFieldsAddr() const {
     return FieldAddrAtOffset(sizeof(RawObject));
@@ -10461,45 +10313,26 @@ bool Function::HasBytecode(RawFunction* function) {
 }
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
 
-intptr_t Field::HostOffset() const {
-  ASSERT(is_instance());  // Valid only for dart instance fields.
-  return (raw_ptr()->host_offset_or_field_id_ * kWordSize);
-}
-
-intptr_t Field::TargetOffset() const {
+intptr_t Field::Offset() const {
   ASSERT(is_instance());  // Valid only for dart instance fields.
-#if !defined(DART_PRECOMPILED_RUNTIME)
-  return (raw_ptr()->target_offset_ * compiler::target::kWordSize);
-#else
-  return HostOffset();
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+  return (raw_ptr()->offset_or_field_id_ * kWordSize);
 }
 
-void Field::SetOffset(intptr_t host_offset_in_bytes,
-                      intptr_t target_offset_in_bytes) const {
+void Field::SetOffset(intptr_t offset_in_bytes) const {
   ASSERT(is_instance());  // Valid only for dart instance fields.
   ASSERT(kWordSize != 0);
-  StoreNonPointer(&raw_ptr()->host_offset_or_field_id_,
-                  host_offset_in_bytes / kWordSize);
-#if !defined(DART_PRECOMPILED_RUNTIME)
-  ASSERT(compiler::target::kWordSize != 0);
-  StoreNonPointer(&raw_ptr()->target_offset_,
-                  target_offset_in_bytes / compiler::target::kWordSize);
-#else
-  ASSERT(host_offset_in_bytes == target_offset_in_bytes);
-#endif  //  !defined(DART_PRECOMPILED_RUNTIME)
+  StoreNonPointer(&raw_ptr()->offset_or_field_id_, offset_in_bytes / kWordSize);
 }
 
 RawInstance* Field::StaticValue() const {
   ASSERT(is_static());  // Valid only for static dart fields.
-  return Isolate::Current()->field_table()->At(
-      raw_ptr()->host_offset_or_field_id_);
+  return Isolate::Current()->field_table()->At(raw_ptr()->offset_or_field_id_);
 }
 
 void Field::set_field_id(intptr_t field_id) const {
   ASSERT(is_static());
   ASSERT(Thread::Current()->IsMutatorThread());
-  StoreNonPointer(&raw_ptr()->host_offset_or_field_id_, field_id);
+  StoreNonPointer(&raw_ptr()->offset_or_field_id_, field_id);
 }
 
 #ifndef DART_PRECOMPILED_RUNTIME
diff --git a/runtime/vm/object_graph.cc b/runtime/vm/object_graph.cc
index 98b112fa4c034..4b38e2db5c216 100644
--- a/runtime/vm/object_graph.cc
+++ b/runtime/vm/object_graph.cc
@@ -1097,7 +1097,7 @@ void HeapSnapshotWriter::Write() {
                 if (field.is_instance()) {
                   intptr_t flags = 1;  // Strong.
                   WriteUnsigned(flags);
-                  intptr_t index = field.HostOffset() / kWordSize - 1;
+                  intptr_t index = field.Offset() / kWordSize - 1;
                   ASSERT(index >= 0);
                   WriteUnsigned(index);
                   str = field.name();
diff --git a/runtime/vm/object_reload.cc b/runtime/vm/object_reload.cc
index 62013273bd48a..afed7443858ac 100644
--- a/runtime/vm/object_reload.cc
+++ b/runtime/vm/object_reload.cc
@@ -663,8 +663,8 @@ class InstanceSizeConflict : public ClassReasonForCancelling {
     return String::NewFormatted("Instance size mismatch between '%s' (%" Pd
                                 ") and replacement "
                                 "'%s' ( %" Pd ")",
-                                from_.ToCString(), from_.host_instance_size(),
-                                to_.ToCString(), to_.host_instance_size());
+                                from_.ToCString(), from_.instance_size(),
+                                to_.ToCString(), to_.instance_size());
   }
 };
 
@@ -748,9 +748,7 @@ bool Class::RequiresInstanceMorphing(const Class& replacement) const {
   // Check that we have the same next field offset. This check is not
   // redundant with the one above because the instance OffsetToFieldMap
   // array length is based on the instance size (which may be aligned up).
-  if (host_next_field_offset() != replacement.host_next_field_offset()) {
-    return true;
-  }
+  if (next_field_offset() != replacement.next_field_offset()) return true;
 
   // Verify that field names / offsets match across the entire hierarchy.
   Field& field = Field::Handle();
@@ -807,7 +805,7 @@ bool Class::CanReloadPreFinalized(const Class& replacement,
     return false;
   }
   // Check the instance sizes are equal.
-  if (host_instance_size() != replacement.host_instance_size()) {
+  if (instance_size() != replacement.instance_size()) {
     context->group_reload_context()->AddReasonForCancelling(
         new (context->zone())
             InstanceSizeConflict(context->zone(), *this, replacement));
diff --git a/runtime/vm/object_test.cc b/runtime/vm/object_test.cc
index a1359fe8a48e0..e16b26459f4f3 100644
--- a/runtime/vm/object_test.cc
+++ b/runtime/vm/object_test.cc
@@ -217,7 +217,7 @@ ISOLATE_UNIT_TEST_CASE(InstanceClass) {
   ClassFinalizer::FinalizeTypesInClass(empty_class);
   empty_class.Finalize();
 
-  EXPECT_EQ(kObjectAlignment, empty_class.host_instance_size());
+  EXPECT_EQ(kObjectAlignment, empty_class.instance_size());
   Instance& instance = Instance::Handle(Instance::New(empty_class));
   EXPECT_EQ(empty_class.raw(), instance.clazz());
 
@@ -242,8 +242,8 @@ ISOLATE_UNIT_TEST_CASE(InstanceClass) {
   one_field_class.Finalize();
   intptr_t header_size = sizeof(RawObject);
   EXPECT_EQ(Utils::RoundUp((header_size + (1 * kWordSize)), kObjectAlignment),
-            one_field_class.host_instance_size());
-  EXPECT_EQ(header_size, field.HostOffset());
+            one_field_class.instance_size());
+  EXPECT_EQ(header_size, field.Offset());
   EXPECT(!one_field_class.is_implemented());
   one_field_class.set_is_implemented();
   EXPECT(one_field_class.is_implemented());
diff --git a/runtime/vm/raw_object.cc b/runtime/vm/raw_object.cc
index f858f65a39406..8ff35b9346ddd 100644
--- a/runtime/vm/raw_object.cc
+++ b/runtime/vm/raw_object.cc
@@ -377,32 +377,14 @@ void RawObject::VisitPointersPrecise(ObjectPointerVisitor* visitor) {
   uword next_field_offset = visitor->isolate()
                                 ->GetClassForHeapWalkAt(class_id)
                                 ->ptr()
-                                ->host_next_field_offset_in_words_
+                                ->next_field_offset_in_words_
                             << kWordSizeLog2;
   ASSERT(next_field_offset > 0);
   uword obj_addr = RawObject::ToAddr(this);
   uword from = obj_addr + sizeof(RawObject);
   uword to = obj_addr + next_field_offset - kWordSize;
-  const auto first = reinterpret_cast<RawObject**>(from);
-  const auto last = reinterpret_cast<RawObject**>(to);
-
-#if defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
-  const auto unboxed_fields_bitmap =
-      visitor->shared_class_table()->GetUnboxedFieldsMapAt(class_id);
-
-  if (!unboxed_fields_bitmap.IsEmpty()) {
-    intptr_t bit = sizeof(RawObject) / kWordSize;
-    for (RawObject** current = first; current <= last; current++) {
-      if (!unboxed_fields_bitmap.Get(bit++)) {
-        visitor->VisitPointer(current);
-      }
-    }
-  } else {
-    visitor->VisitPointers(first, last);
-  }
-#else
-  visitor->VisitPointers(first, last);
-#endif  // defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
+  visitor->VisitPointers(reinterpret_cast<RawObject**>(from),
+                         reinterpret_cast<RawObject**>(to));
 }
 
 bool RawObject::FindObject(FindObjectVisitor* visitor) {
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index 7ba8300298082..acfaf53f52758 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -474,27 +474,10 @@ class RawObject {
     uword obj_addr = ToAddr(this);
     uword from = obj_addr + sizeof(RawObject);
     uword to = obj_addr + instance_size - kWordSize;
-    const auto first = reinterpret_cast<RawObject**>(from);
-    const auto last = reinterpret_cast<RawObject**>(to);
-
-#if defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
-    const auto unboxed_fields_bitmap =
-        visitor->shared_class_table()->GetUnboxedFieldsMapAt(class_id);
-
-    if (!unboxed_fields_bitmap.IsEmpty()) {
-      intptr_t bit = sizeof(RawObject) / kWordSize;
-      for (RawObject** current = first; current <= last; current++) {
-        if (!unboxed_fields_bitmap.Get(bit++)) {
-          visitor->VisitPointer(current);
-        }
-      }
-    } else {
-      visitor->VisitPointers(first, last);
-    }
-#else
+
     // Call visitor function virtually
-    visitor->VisitPointers(first, last);
-#endif  // defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
+    visitor->VisitPointers(reinterpret_cast<RawObject**>(from),
+                           reinterpret_cast<RawObject**>(to));
 
     return instance_size;
   }
@@ -512,27 +495,10 @@ class RawObject {
     uword obj_addr = ToAddr(this);
     uword from = obj_addr + sizeof(RawObject);
     uword to = obj_addr + instance_size - kWordSize;
-    const auto first = reinterpret_cast<RawObject**>(from);
-    const auto last = reinterpret_cast<RawObject**>(to);
-
-#if defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
-    const auto unboxed_fields_bitmap =
-        visitor->shared_class_table()->GetUnboxedFieldsMapAt(class_id);
-
-    if (!unboxed_fields_bitmap.IsEmpty()) {
-      intptr_t bit = sizeof(RawObject) / kWordSize;
-      for (RawObject** current = first; current <= last; current++) {
-        if (!unboxed_fields_bitmap.Get(bit++)) {
-          visitor->V::VisitPointers(current, current);
-        }
-      }
-    } else {
-      visitor->V::VisitPointers(first, last);
-    }
-#else
+
     // Call visitor function non-virtually
-    visitor->V::VisitPointers(first, last);
-#endif  // defined(SUPPORT_UNBOXED_INSTANCE_FIELDS)
+    visitor->V::VisitPointers(reinterpret_cast<RawObject**>(from),
+                              reinterpret_cast<RawObject**>(to));
 
     return instance_size;
   }
@@ -848,32 +814,14 @@ class RawClass : public RawObject {
 
   TokenPosition token_pos_;
   TokenPosition end_token_pos_;
-
+  int32_t instance_size_in_words_;  // Size if fixed len or 0 if variable len.
+  int32_t type_arguments_field_offset_in_words_;  // Offset of type args fld.
+  int32_t next_field_offset_in_words_;  // Offset of the next instance field.
   classid_t id_;                // Class Id, also index in the class table.
   int16_t num_type_arguments_;  // Number of type arguments in flattened vector.
   uint16_t num_native_fields_;
   uint32_t state_bits_;
 
-  // Size if fixed len or 0 if variable len.
-  int32_t host_instance_size_in_words_;
-
-  // Offset of type args fld.
-  int32_t host_type_arguments_field_offset_in_words_;
-
-  // Offset of the next instance field.
-  int32_t host_next_field_offset_in_words_;
-
-#if !defined(DART_PRECOMPILED_RUNTIME)
-  // Size if fixed len or 0 if variable len (target).
-  int32_t target_instance_size_in_words_;
-
-  // Offset of type args fld.
-  int32_t target_type_arguments_field_offset_in_words_;
-
-  // Offset of the next instance field (target).
-  int32_t target_next_field_offset_in_words_;
-#endif  // !defined(DART_PRECOMPILED_RUNTIME)
-
 #if !defined(DART_PRECOMPILED_RUNTIME)
   typedef BitField<uint32_t, bool, 0, 1> IsDeclaredInBytecode;
   typedef BitField<uint32_t, uint32_t, 1, 31> BinaryDeclarationOffset;
@@ -1229,16 +1177,11 @@ class RawField : public RawObject {
   // field.
   int8_t static_type_exactness_state_;
 
-  uint16_t kind_bits_;  // static, final, const, has initializer....
-
   // - for instance fields: offset in words to the value in the class instance.
   // - for static fields: index into field_table.
-  intptr_t host_offset_or_field_id_;
+  intptr_t offset_or_field_id_;
 
-#if !defined(DART_PRECOMPILED_RUNTIME)
-  // for instance fields, the offset in words in the target architecture
-  int32_t target_offset_;
-#endif  // !defined(DART_PRECOMPILED_RUNTIME)
+  uint16_t kind_bits_;  // static, final, const, has initializer....
 
   friend class CidRewriteVisitor;
 };
@@ -2315,7 +2258,6 @@ class RawDouble : public RawNumber {
 
   friend class Api;
   friend class SnapshotReader;
-  friend class Class;
 };
 COMPILE_ASSERT(sizeof(RawDouble) == 16);
 
@@ -2586,7 +2528,6 @@ class RawFloat32x4 : public RawInstance {
   ALIGN8 float value_[4];
 
   friend class SnapshotReader;
-  friend class Class;
 
  public:
   float x() const { return value_[0]; }
@@ -2619,7 +2560,6 @@ class RawFloat64x2 : public RawInstance {
   ALIGN8 double value_[2];
 
   friend class SnapshotReader;
-  friend class Class;
 
  public:
   double x() const { return value_[0]; }
diff --git a/runtime/vm/snapshot.cc b/runtime/vm/snapshot.cc
index cc04a43317231..75e507ca38caf 100644
--- a/runtime/vm/snapshot.cc
+++ b/runtime/vm/snapshot.cc
@@ -593,59 +593,47 @@ RawObject* SnapshotReader::ReadInstance(intptr_t object_id,
     ASSERT(!cls_.IsNull());
     // Closure instances are handled by Closure::ReadFrom().
     ASSERT(!cls_.IsClosureClass());
-    instance_size = cls_.host_instance_size();
+    instance_size = cls_.instance_size();
     ASSERT(instance_size > 0);
     // Allocate the instance and read in all the fields for the object.
     *result ^= Object::Allocate(cls_.id(), instance_size, Heap::kNew);
   } else {
     cls_ ^= ReadObjectImpl(kAsInlinedObject);
     ASSERT(!cls_.IsNull());
-    instance_size = cls_.host_instance_size();
+    instance_size = cls_.instance_size();
   }
   if (cls_.id() == set_class_.id()) {
     EnqueueRehashingOfSet(*result);
   }
   if (!as_reference) {
     // Read all the individual fields for inlined objects.
-    intptr_t next_field_offset = cls_.host_next_field_offset();
+    intptr_t next_field_offset = cls_.next_field_offset();
 
-    intptr_t type_argument_field_offset =
-        cls_.host_type_arguments_field_offset();
+    intptr_t type_argument_field_offset = cls_.type_arguments_field_offset();
     ASSERT(next_field_offset > 0);
     // Instance::NextFieldOffset() returns the offset of the first field in
     // a Dart object.
     bool read_as_reference = RawObject::IsCanonical(tags) ? false : true;
     intptr_t offset = Instance::NextFieldOffset();
     intptr_t result_cid = result->GetClassId();
-
-    const auto unboxed_fields =
-        isolate()->shared_class_table()->GetUnboxedFieldsMapAt(result_cid);
-
     while (offset < next_field_offset) {
-      if (unboxed_fields.Get(offset / kWordSize)) {
-        uword* p = reinterpret_cast<uword*>(result->raw_value() -
-                                            kHeapObjectTag + offset);
-        // Reads 32 bits of the unboxed value at a time
-        *p = ReadWordWith32BitReads();
-      } else {
-        pobj_ = ReadObjectImpl(read_as_reference);
-        result->SetFieldAtOffset(offset, pobj_);
-        if ((offset != type_argument_field_offset) &&
-            (kind_ == Snapshot::kMessage) && isolate()->use_field_guards()) {
-          // TODO(fschneider): Consider hoisting these lookups out of the loop.
-          // This would involve creating a handle, since cls_ can't be reused
-          // across the call to ReadObjectImpl.
-          cls_ = isolate()->class_table()->At(result_cid);
-          array_ = cls_.OffsetToFieldMap();
-          field_ ^= array_.At(offset >> kWordSizeLog2);
-          ASSERT(!field_.IsNull());
-          ASSERT(field_.HostOffset() == offset);
-          obj_ = pobj_.raw();
-          field_.RecordStore(obj_);
-        }
-        // TODO(fschneider): Verify the guarded cid and length for other kinds
-        // of snapshot (kFull, kScript) with asserts.
+      pobj_ = ReadObjectImpl(read_as_reference);
+      result->SetFieldAtOffset(offset, pobj_);
+      if ((offset != type_argument_field_offset) &&
+          (kind_ == Snapshot::kMessage) && isolate()->use_field_guards()) {
+        // TODO(fschneider): Consider hoisting these lookups out of the loop.
+        // This would involve creating a handle, since cls_ can't be reused
+        // across the call to ReadObjectImpl.
+        cls_ = isolate()->class_table()->At(result_cid);
+        array_ = cls_.OffsetToFieldMap();
+        field_ ^= array_.At(offset >> kWordSizeLog2);
+        ASSERT(!field_.IsNull());
+        ASSERT(field_.Offset() == offset);
+        obj_ = pobj_.raw();
+        field_.RecordStore(obj_);
       }
+      // TODO(fschneider): Verify the guarded cid and length for other kinds of
+      // snapshot (kFull, kScript) with asserts.
       offset += kWordSize;
     }
     if (RawObject::IsCanonical(tags)) {
@@ -1451,7 +1439,7 @@ void SnapshotWriter::WriteInstance(RawObject* raw,
     // Write out the class information for this object.
     WriteObjectImpl(cls, kAsInlinedObject);
   } else {
-    intptr_t next_field_offset = Class::host_next_field_offset_in_words(cls)
+    intptr_t next_field_offset = cls->ptr()->next_field_offset_in_words_
                                  << kWordSizeLog2;
     ASSERT(next_field_offset > 0);
 
@@ -1467,26 +1455,15 @@ void SnapshotWriter::WriteInstance(RawObject* raw,
     // Write out the class information for this object.
     WriteObjectImpl(cls, kAsInlinedObject);
 
-    const auto unboxed_fields =
-        isolate()->shared_class_table()->GetUnboxedFieldsMapAt(cls->ptr()->id_);
-
     // Write out all the fields for the object.
     // Instance::NextFieldOffset() returns the offset of the first field in
     // a Dart object.
     bool write_as_reference = RawObject::IsCanonical(tags) ? false : true;
-
     intptr_t offset = Instance::NextFieldOffset();
     while (offset < next_field_offset) {
-      if (unboxed_fields.Get(offset / kWordSize)) {
-        // Writes 32 bits of the unboxed value at a time
-        const uword value = *reinterpret_cast<uword*>(
-            reinterpret_cast<uword>(raw->ptr()) + offset);
-        WriteWordWith32BitWrites(value);
-      } else {
-        RawObject* raw_obj = *reinterpret_cast<RawObject**>(
-            reinterpret_cast<uword>(raw->ptr()) + offset);
-        WriteObjectImpl(raw_obj, write_as_reference);
-      }
+      RawObject* raw_obj = *reinterpret_cast<RawObject**>(
+          reinterpret_cast<uword>(raw->ptr()) + offset);
+      WriteObjectImpl(raw_obj, write_as_reference);
       offset += kWordSize;
     }
   }
diff --git a/runtime/vm/snapshot.h b/runtime/vm/snapshot.h
index 3c528e8ec4c88..1242943f2a802 100644
--- a/runtime/vm/snapshot.h
+++ b/runtime/vm/snapshot.h
@@ -272,8 +272,6 @@ class BaseReader {
     return SerializedHeaderData::decode(value);
   }
 
-  uword ReadWordWith32BitReads() { return stream_.ReadWordWith32BitReads(); }
-
  private:
   ReadStream stream_;  // input stream.
 };
@@ -531,10 +529,6 @@ class BaseWriter : public StackResource {
     stream_.WriteBytes(reinterpret_cast<const uint8_t*>(&value), sizeof(value));
   }
 
-  void WriteWordWith32BitWrites(uword value) {
-    stream_.WriteWordWith32BitWrites(value);
-  }
-
  protected:
   BaseWriter(ReAlloc alloc, DeAlloc dealloc, intptr_t initial_size)
       : StackResource(Thread::Current()),
diff --git a/runtime/vm/visitor.cc b/runtime/vm/visitor.cc
deleted file mode 100644
index 0fd28d43857bc..0000000000000
--- a/runtime/vm/visitor.cc
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-#include "vm/visitor.h"
-
-#include "vm/isolate.h"
-
-namespace dart {
-
-ObjectPointerVisitor::ObjectPointerVisitor(Isolate* isolate)
-    : isolate_(isolate),
-      gc_root_type_("unknown"),
-      shared_class_table_(isolate->shared_class_table()) {}
-
-}  // namespace dart
diff --git a/runtime/vm/visitor.h b/runtime/vm/visitor.h
index 9d5bf750d825c..cd0e9671b0f3d 100644
--- a/runtime/vm/visitor.h
+++ b/runtime/vm/visitor.h
@@ -6,7 +6,6 @@
 #define RUNTIME_VM_VISITOR_H_
 
 #include "vm/allocation.h"
-#include "vm/class_table.h"
 #include "vm/globals.h"
 #include "vm/growable_array.h"
 
@@ -21,7 +20,8 @@ class RawTypedDataView;
 // An object pointer visitor interface.
 class ObjectPointerVisitor {
  public:
-  explicit ObjectPointerVisitor(Isolate* isolate);
+  explicit ObjectPointerVisitor(Isolate* isolate)
+      : isolate_(isolate), gc_root_type_("unknown") {}
   virtual ~ObjectPointerVisitor() {}
 
   Isolate* isolate() const { return isolate_; }
@@ -54,14 +54,9 @@ class ObjectPointerVisitor {
 
   virtual bool visit_weak_persistent_handles() const { return false; }
 
-  const SharedClassTable* shared_class_table() const {
-    return shared_class_table_;
-  }
-
  private:
   Isolate* isolate_;
   const char* gc_root_type_;
-  SharedClassTable* shared_class_table_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectPointerVisitor);
 };
diff --git a/runtime/vm/vm_sources.gni b/runtime/vm/vm_sources.gni
index b7d3f4e2a1bea..9c5f7276c205b 100644
--- a/runtime/vm/vm_sources.gni
+++ b/runtime/vm/vm_sources.gni
@@ -357,7 +357,6 @@ vm_sources = [
   "virtual_memory_fuchsia.cc",
   "virtual_memory_posix.cc",
   "virtual_memory_win.cc",
-  "visitor.cc",
   "visitor.h",
   "zone.cc",
   "zone.h",
diff --git a/tests/lib_2/isolate/unboxed_double_snapshot_writer_test.dart b/tests/lib_2/isolate/unboxed_double_snapshot_writer_test.dart
deleted file mode 100644
index 132ad6bf7eb6e..0000000000000
--- a/tests/lib_2/isolate/unboxed_double_snapshot_writer_test.dart
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'dart:async';
-import 'dart:isolate';
-import 'dart:typed_data';
-
-import 'package:expect/expect.dart';
-
-double getDoubleWithHeapObjectTag() {
-  final bd = ByteData(8);
-  bd.setUint64(0, 0x8000000000000001, Endian.host);
-  final double v = bd.getFloat64(0, Endian.host);
-  return v;
-}
-
-class Foo {
-  final double x = getDoubleWithHeapObjectTag();
-  final String name = "Foo Class";
-  Foo();
-}
-
-main(args) async {
-  final receivePort = new ReceivePort();
-
-  receivePort.sendPort.send(Foo());
-  final it = StreamIterator(receivePort);
-  Expect.isTrue(await it.moveNext());
-  final Foo receivedFoo = it.current as Foo;
-  Expect.equals(receivedFoo.x, getDoubleWithHeapObjectTag());
-  Expect.equals(receivedFoo.name, "Foo Class");
-  await it.cancel();
-}