Array index computation dehoisting.

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 213 matching lines @@
   int DefineDeoptimizationLiteral(Handle<Object> literal);
 
   void PopulateDeoptimizationLiteralsWithInlinedFunctions();
 
   Register ToRegister(int index) const;
   XMMRegister ToDoubleRegister(int index) const;
   Operand BuildFastArrayOperand(
       LOperand* elements_pointer,
       LOperand* key,
       ElementsKind elements_kind,
-      uint32_t offset);
+      uint32_t offset,
+      uint32_t additional_index = 0);
 
   // Specific math operations - used from DoUnaryMathOperation.
   void EmitIntegerMathAbs(LUnaryMathOperation* instr);
   void DoMathAbs(LUnaryMathOperation* instr);
   void DoMathFloor(LUnaryMathOperation* instr);
   void DoMathRound(LUnaryMathOperation* instr);
   void DoMathSqrt(LUnaryMathOperation* instr);
   void DoMathPowHalf(LUnaryMathOperation* instr);
   void DoMathLog(LUnaryMathOperation* instr);
   void DoMathTan(LUnaryMathOperation* instr);
@@ skipping 152 matching lines @@
   LCodeGen* codegen_;
   Label entry_;
   Label exit_;
   Label* external_exit_;
   int instruction_index_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_LITHIUM_CODEGEN_X64_H_