Fix x64 build.

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 467 matching lines @@
   // Call a code stub that has already been prepared for calling (via
   // PrepareForCall).
   Result RawCallStub(CodeStub* stub);
 
   // Calls a code object which has already been prepared for calling
   // (via PrepareForCall).
   Result RawCallCodeObject(Handle<Code> code, RelocInfo::Mode rmode);
 
   bool Equals(VirtualFrame* other);
 
-  // Perform initialization required during entry frame computation
-  // after setting the virtual frame element at index in frame to be
-  // target.
-  void InitializeEntryElement(int index, FrameElement* target) {
-    elements_[index].clear_copied();
-    if (target->is_register()) {
-      register_locations_[target->reg().code()] = index;
-    } else if (target->is_copy()) {
-      elements_[target->index()].set_copied();
-    }
-  }
-
   friend class JumpTarget;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_VIRTUAL_FRAME_X64_H_