Enable remaining execution tests on x64.

runtime/vm/heap_test.cc

 // Copyright (c) 2012, 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 "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/heap.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
-#if defined(TARGET_ARCH_IA32)
+// Only ia32 and x64 can run execution tests.
+#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64)
 TEST_CASE(OldGC) {
   const char* kScriptChars =
   "class HeapTester {\n"
   "  static void main() {\n"
   "    return [1, 2, 3];\n"
   "  }\n"
   "}\n";
   FLAG_verbose_gc = true;
   Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
   Dart_Handle result = Dart_InvokeStatic(lib,
@@ skipping 28 matching lines @@
   EXPECT_VALID(result);
   EXPECT(!Dart_IsNull(result));
   EXPECT(Dart_IsList(result));
   Isolate* isolate = Isolate::Current();
   Heap* heap = isolate->heap();
   heap->CollectGarbage(Heap::kOld);
   Dart_ExitScope();
   heap->CollectGarbage(Heap::kOld);
 }
 
-#endif  // TARGET_ARCH_IA32
+#endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 }