[x64] Improve key value sign-extension of dehoisted LoadKeyed/StoreKeyed

src/x64/lithium-codegen-x64.h

 // Copyright 2012 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 141 matching lines @@
   void Abort(BailoutReason reason);
 
   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
 
 
   void SaveCallerDoubles();
   void RestoreCallerDoubles();
 
   // Code generation passes.  Returns true if code generation should
   // continue.
+  void GenerateBodyInstructionPost(LInstruction* instr) V8_OVERRIDE;
   bool GeneratePrologue();
   bool GenerateDeferredCode();
   bool GenerateJumpTable();
   bool GenerateSafepointTable();
 
   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
   void GenerateOsrPrologue();
 
   enum SafepointMode {
     RECORD_SIMPLE_SAFEPOINT,
@@ skipping 239 matching lines @@
   Label entry_;
   Label exit_;
   Label done_;
   Label* external_exit_;
   int instruction_index_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_LITHIUM_CODEGEN_X64_H_