Get rid of the HInstanceSize instruction.

src/x64/lithium-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 87 matching lines @@
   V(FunctionLiteral)                            \
   V(GetCachedArrayIndex)                        \
   V(GlobalObject)                               \
   V(GlobalReceiver)                             \
   V(Goto)                                       \
   V(HasCachedArrayIndexAndBranch)               \
   V(HasInstanceTypeAndBranch)                   \
   V(InnerAllocatedObject)                       \
   V(InstanceOf)                                 \
   V(InstanceOfKnownGlobal)                      \
-  V(InstanceSize)                               \
   V(InstructionGap)                             \
   V(Integer32ToDouble)                          \
   V(Integer32ToSmi)                             \
   V(InvokeFunction)                             \
   V(IsConstructCallAndBranch)                   \
   V(IsObjectAndBranch)                          \
   V(IsStringAndBranch)                          \
   V(IsSmiAndBranch)                             \
   V(IsUndetectableAndBranch)                    \
   V(Label)                                      \
@@ skipping 952 matching lines @@
   virtual void SetDeferredLazyDeoptimizationEnvironment(
       LEnvironment* env) V8_OVERRIDE {
     lazy_deopt_env_ = env;
   }
 
  private:
   LEnvironment* lazy_deopt_env_;
 };
 
 
-class LInstanceSize V8_FINAL : public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LInstanceSize(LOperand* object) {
-    inputs_[0] = object;
-  }
-
-  LOperand* object() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(InstanceSize, "instance-size")
-  DECLARE_HYDROGEN_ACCESSOR(InstanceSize)
-};
-
-
 class LBoundsCheck V8_FINAL : public LTemplateInstruction<0, 2, 0> {
  public:
   LBoundsCheck(LOperand* index, LOperand* length) {
     inputs_[0] = index;
     inputs_[1] = length;
   }
 
   LOperand* index() { return inputs_[0]; }
   LOperand* length() { return inputs_[1]; }
 
@@ skipping 1620 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_