Revert of Compiling an array literal should be context-independent. (…

…patchset #5 id:80001 of https://codereview.chromium.org/2479123002/ )

Reason for revert:
speculative revert to fix https://uberchromegw.corp.google.com/i/client.v8/builders/V8%20Mac%20GC%20Stress/builds/9646/steps/Mjsunit%20%28flakes%29/logs/debug-scopes

Original issue's description:
> Compiling an array literal should be context-independent.
>
> We are removing use of the debugger context. When the debugger triggers
> compilation, we may not have a context from which to create a JSArray.
>
> R=ishell@chromium.org

TBR=ishell@chromium.org,verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2481363009
Cr-Commit-Position: refs/heads/master@{#40906}

src/ast/ast.cc

@@ -14,7 +14,6 @@
 #include "src/code-stubs.h"
 #include "src/contexts.h"
 #include "src/conversions.h"
-#include "src/elements.h"
 #include "src/property-details.h"
 #include "src/property.h"
 #include "src/string-stream.h"
@@ -581,9 +580,11 @@ void ArrayLiteral::BuildConstantElements(Isolate* isolate) {
   if (!constant_elements_.is_null()) return;
 
   int constants_length = values()->length();
-  ElementsKind kind = FIRST_FAST_ELEMENTS_KIND;
-  Handle<FixedArray> fixed_array =
-      isolate->factory()->NewFixedArrayWithHoles(constants_length);
+
+  // Allocate a fixed array to hold all the object literals.
+  Handle<JSArray> array = isolate->factory()->NewJSArray(
+      FAST_HOLEY_SMI_ELEMENTS, constants_length, constants_length,
+      INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE);
 
   // Fill in the literals.
   bool is_simple = true;
@@ -614,34 +615,29 @@ void ArrayLiteral::BuildConstantElements(Isolate* isolate) {
       is_simple = false;
     }
 
-    kind = GetMoreGeneralElementsKind(kind,
-                                      boilerplate_value->OptimalElementsKind());
-    fixed_array->set(array_index, *boilerplate_value);
+    JSObject::AddDataElement(array, array_index, boilerplate_value, NONE)
+        .Assert();
   }
 
-  if (is_holey) kind = GetHoleyElementsKind(kind);
+  JSObject::ValidateElements(array);
+  Handle<FixedArrayBase> element_values(array->elements());
 
   // Simple and shallow arrays can be lazily copied, we transform the
   // elements array to a copy-on-write array.
   if (is_simple && depth_acc == 1 && array_index > 0 &&
-      IsFastSmiOrObjectElementsKind(kind)) {
-    fixed_array->set_map(isolate->heap()->fixed_cow_array_map());
-  }
-
-  Handle<FixedArrayBase> elements = fixed_array;
-  if (IsFastDoubleElementsKind(kind)) {
-    ElementsAccessor* accessor = ElementsAccessor::ForKind(kind);
-    elements = isolate->factory()->NewFixedDoubleArray(constants_length);
-    // We are copying from non-fast-double to fast-double.
-    ElementsKind from_kind = TERMINAL_FAST_ELEMENTS_KIND;
-    accessor->CopyElements(fixed_array, from_kind, elements, constants_length);
+      array->HasFastSmiOrObjectElements()) {
+    element_values->set_map(isolate->heap()->fixed_cow_array_map());
   }
 
   // Remember both the literal's constant values as well as the ElementsKind
   // in a 2-element FixedArray.
   Handle<FixedArray> literals = isolate->factory()->NewFixedArray(2, TENURED);
+
+  ElementsKind kind = array->GetElementsKind();
+  kind = is_holey ? GetHoleyElementsKind(kind) : GetPackedElementsKind(kind);
+
   literals->set(0, Smi::FromInt(kind));
-  literals->set(1, *elements);
+  literals->set(1, *element_values);
 
   constant_elements_ = literals;
   set_is_simple(is_simple);

src/elements.cc

@@ -973,12 +973,6 @@ class ElementsAccessorBase : public ElementsAccessor {
                                packed_size, copy_size);
   }
 
-  void CopyElements(Handle<FixedArrayBase> source, ElementsKind source_kind,
-                    Handle<FixedArrayBase> destination, int size) {
-    Subclass::CopyElementsImpl(*source, 0, *destination, source_kind, 0,
-                               kPackedSizeNotKnown, size);
-  }
-
   Handle<SeededNumberDictionary> Normalize(Handle<JSObject> object) final {
     return Subclass::NormalizeImpl(object, handle(object->elements()));
   }

src/elements.h

@@ -170,10 +170,6 @@ class ElementsAccessor {
                                       Handle<Object> value, uint32_t start,
                                       uint32_t length) = 0;
 
-  virtual void CopyElements(Handle<FixedArrayBase> source,
-                            ElementsKind source_kind,
-                            Handle<FixedArrayBase> destination, int size) = 0;
-
  protected:
   friend class LookupIterator;