X64: Convert smis to holding 32 bits of payload.

src/x64/virtual-frame-x64.h

 // Copyright 2009 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 359 matching lines @@
   // emit a corresponding pop instruction.
   void EmitPop(Register reg);
   void EmitPop(const Operand& operand);
 
   // Push an element on top of the expression stack and emit a
   // corresponding push instruction.
   void EmitPush(Register reg);
   void EmitPush(const Operand& operand);
   void EmitPush(Heap::RootListIndex index);
   void EmitPush(Immediate immediate);
+  void EmitPush(Smi* value);
   // Uses kScratchRegister, emits appropriate relocation info.
   void EmitPush(Handle<Object> value);
 
   // Push an element on the virtual frame.
   void Push(Register reg);
   void Push(Handle<Object> value);
   void Push(Smi* value) { Push(Handle<Object>(value)); }
 
   // Pushing a result invalidates it (its contents become owned by the
   // frame).
@@ skipping 157 matching lines @@
 
   // Classes that need raw access to the elements_ array.
   friend class DeferredCode;
   friend class JumpTarget;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_VIRTUAL_FRAME_X64_H_