X64 implementation: Emit correct merge code for virtual frames at CFG merges.

src/x64/macro-assembler-x64.h

 // Copyright 2006-2008 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 140 matching lines @@
   // Store the code object for the given builtin in the target register.
   void GetBuiltinEntry(Register target, Builtins::JavaScript id);
 
   // ---------------------------------------------------------------------------
   // Macro instructions
 
   // Expression support
   void Set(Register dst, int64_t x);
   void Set(const Operand& dst, int64_t x);
 
+  // Handle support
+  bool IsUnsafeSmi(Smi* value);
+  bool IsUnsafeSmi(Handle<Object> value) {
+    return IsUnsafeSmi(Smi::cast(*value));
+  }
+
+  void LoadUnsafeSmi(Register dst, Smi* source);
+  void LoadUnsafeSmi(Register dst, Handle<Object> source) {
+    LoadUnsafeSmi(dst, Smi::cast(*source));
+  }
+
+  void Move(Register dst, Handle<Object> source);
+  void Move(const Operand& dst, Handle<Object> source);
+  void Cmp(Register dst, Handle<Object> source);
+
   // Control Flow
   void Jump(Address destination, RelocInfo::Mode rmode);
   void Jump(ExternalReference ext);
   void Jump(Handle<Code> code_object, RelocInfo::Mode rmode);
 
   void Call(Address destination, RelocInfo::Mode rmode);
   void Call(ExternalReference ext);
   void Call(Handle<Code> code_object, RelocInfo::Mode rmode);
 
   // Compare object type for heap object.
@@ skipping 218 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_