[Interpreter] Adds an optimization to remove redundant Ldar/Star.

src/interpreter/bytecode-array-builder.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 #define V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 
 #include <vector>
 
 #include "src/ast.h"
@@ skipping 233 matching lines @@
                  ZoneVector<uint8_t>::iterator jump_location);
 
   void LeaveBasicBlock();
   void EnsureReturn();
 
   bool OperandIsValid(Bytecode bytecode, int operand_index,
                       uint32_t operand_value) const;
   bool LastBytecodeInSameBlock() const;
 
   bool NeedToBooleanCast();
+  bool IsRegisterInAccumulator(Register reg);
 
   int BorrowTemporaryRegister();
   void ReturnTemporaryRegister(int reg_index);
   int PrepareForConsecutiveTemporaryRegisters(size_t count);
   void BorrowConsecutiveTemporaryRegister(int reg_index);
   bool TemporaryRegisterIsLive(Register reg) const;
 
   Register first_temporary_register() const;
   Register last_temporary_register() const;
 
@@ skipping 86 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(TemporaryRegisterScope);
 };
 
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_