VM: Reland Inline instance object hash code into object header on 64bit.

runtime/vm/stub_code_ia32.cc

 // Copyright (c) 2013, 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/globals.h"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 1060 matching lines @@
     } else {
       __ j(ABOVE_EQUAL, &slow_case);
     }
     __ movl(Address(EDI, Heap::TopOffset(space)), EBX);
     NOT_IN_PRODUCT(__ UpdateAllocationStats(cls.id(), ECX, space));
 
     // EAX: new object start (untagged).
     // EBX: next object start.
     // EDX: new object type arguments (if is_cls_parameterized).
     // Set the tags.
-    uword tags = 0;
+    uint32_t tags = 0;
     tags = RawObject::SizeTag::update(instance_size, tags);
     ASSERT(cls.id() != kIllegalCid);
     tags = RawObject::ClassIdTag::update(cls.id(), tags);
     __ movl(Address(EAX, Instance::tags_offset()), Immediate(tags));
     __ addl(EAX, Immediate(kHeapObjectTag));
 
     // Initialize the remaining words of the object.
 
     // EAX: new object (tagged).
     // EBX: next object start.
@@ skipping 1044 matching lines @@
 }
 
 
 void StubCode::GenerateAsynchronousGapMarkerStub(Assembler* assembler) {
   __ int3();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32