Make x64 to use the RecordWrite stub. This is a step towards getting

src/ia32/macro-assembler-ia32.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 60 matching lines @@
 
   void IncrementalMarkingRecordWriteHelper(Register object,
                                            Register value,
                                            Register address);
 
   enum RememberedSetFinalAction {
     kReturnAtEnd,
     kFallThroughAtEnd
   };
 
-  // For page containing |object| mark region covering |addr| dirty.
-  // RememberedSetHelper only works if the object is not in new
-  // space.
+  // Record in the remembered set the fact that we have a pointer to new space
+  // at the address pointed to by the addr register.  Only works if addr is not
+  // in new space.
   void RememberedSetHelper(Register addr,
                            Register scratch,
                            SaveFPRegsMode save_fp,
                            RememberedSetFinalAction and_then);
 
   void CheckPageFlag(Register object,
                      Register scratch,
                      MemoryChunk::MemoryChunkFlags flag,
                      Condition cc,
                      Label* condition_met,
@@ skipping 37 matching lines @@
 
   // Checks whether an object is data-only, ie it does need to be scanned by the
   // garbage collector.
   void IsDataObject(Register value,
                     Register scratch,
                     Label* not_data_object,
                     Label::Distance not_data_object_distance);
 
   // Notify the garbage collector that we wrote a pointer into an object.
   // |object| is the object being stored into, |value| is the object being
-  // stored.  All registers are clobbered by the operation.  RecordWriteField
-  // filters out smis so it does not update the write barrier if the value is a
-  // smi.  The offset is the offset from the start of the object, not the offset
-  // from the tagged HeapObject pointer.  For use with FieldOperand(reg, off).
+  // stored.  value and scratch registers are clobbered by the operation.
+  // The offset is the offset from the start of the object, not the offset from
+  // the tagged HeapObject pointer.  For use with FieldOperand(reg, off).
   void RecordWriteField(
       Register object,
       int offset,
       Register value,
       Register scratch,
       SaveFPRegsMode save_fp,
       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
       SmiCheck smi_check = INLINE_SMI_CHECK);
 
   // As above, but the offset has the tag presubtracted.  For use with
@@ skipping 717 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_MACRO_ASSEMBLER_IA32_H_