[vm] Check for undefined symbols in assembly snapshots

We don't check undefined symbols in our assembly snapshots. We
currently never emit undefined symbols, because Dart code only refers
to Dart code statically.

When adding static linking, we would like to have the option to have
PC relative calls to native libraries provided as relocatable files
(object files or static libraries).

Not checking would compile the symbols to dynamic linker, but we don't
support that `dart compile exe` at the moment. So we should add this
sanity check.

Also: Removes unused imports in relevant test.

Bug: #49418
Change-Id: I10701b82a1e8a06ce41271bd9183064addfb88f4
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try,vm-kernel-precomp-nnbd-linux-debug-x64-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-precomp-mac-product-x64-try,vm-kernel-precomp-dwarf-linux-product-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/251261
Reviewed-by: Tess Strickland <sstrickl@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Jonas Termansen <sortie@google.com>

pkg/test_runner/lib/src/compiler_configuration.dart

@@ -963,12 +963,14 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
   Command computeAssembleCommand(String tempDir, List arguments,
       Map<String, String> environmentOverrides) {
     late String cc;
-    String? shared, ldFlags;
+    String? shared;
+    var ldFlags = <String>[];
     List<String>? target;
     if (_isAndroid) {
       cc = "$ndkPath/toolchains/$abiTriple-4.9/prebuilt/"
           "$host-x86_64/bin/$abiTriple-gcc";
       shared = '-shared';
+      ldFlags.add('-Wl,--no-undefined');
     } else if (Platform.isLinux) {
       if (_isSimArm || (_isArm && _configuration.useQemu)) {
         cc = 'arm-linux-gnueabihf-gcc';
@@ -982,11 +984,13 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
         cc = 'gcc';
       }
       shared = '-shared';
+      ldFlags.add('-Wl,--no-undefined');
     } else if (Platform.isMacOS) {
       cc = 'clang';
       shared = '-dynamiclib';
+      ldFlags.add('-Wl,-undefined,error');
       // Tell Mac linker to give up generating eh_frame from dwarf.
-      ldFlags = '-Wl,-no_compact_unwind';
+      ldFlags.add('-Wl,-no_compact_unwind');
       if ({Architecture.arm64, Architecture.arm64c}
           .contains(_configuration.architecture)) {
         target = ['-arch', 'arm64'];
@@ -1022,7 +1026,7 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
     var args = [
       if (target != null) ...target,
       if (ccFlags != null) ccFlags,
-      if (ldFlags != null) ldFlags,
+      ...ldFlags,
       shared,
       '-o',
       '$tempDir/out.aotsnapshot',

runtime/tests/vm/dart/run_appended_aot_snapshot_test.dart

@@ -4,7 +4,6 @@
 
 import 'dart:async';
 import 'dart:io';
-import 'dart:typed_data';
 
 import 'package:dart2native/dart2native.dart';
 import 'package:path/path.dart' as path;

runtime/tests/vm/dart_2/run_appended_aot_snapshot_test.dart

@@ -6,7 +6,6 @@
 
 import 'dart:async';
 import 'dart:io';
-import 'dart:typed_data';
 
 import 'package:dart2native/dart2native.dart';
 import 'package:path/path.dart' as path;