Remove the unused HElementsKind instruction.

src/hydrogen-instructions.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 91 matching lines @@
   V(CompareObjectEqAndBranch)                  \
   V(CompareMap)                                \
   V(Constant)                                  \
   V(Context)                                   \
   V(DateField)                                 \
   V(DebugBreak)                                \
   V(DeclareGlobals)                            \
   V(Deoptimize)                                \
   V(Div)                                       \
   V(DummyUse)                                  \
-  V(ElementsKind)                              \
   V(EnterInlined)                              \
   V(EnvironmentMarker)                         \
   V(ForceRepresentation)                       \
   V(ForInCacheArray)                           \
   V(ForInPrepareMap)                           \
   V(FunctionLiteral)                           \
   V(GetCachedArrayIndex)                       \
   V(Goto)                                      \
   V(HasCachedArrayIndexAndBranch)              \
   V(HasInstanceTypeAndBranch)                  \
@@ skipping 2409 matching lines @@
       : HUnaryOperation(value, HType::Smi()) {
     set_representation(Representation::Smi());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnMaps);
   }
 
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
-class HElementsKind V8_FINAL : public HUnaryOperation {
- public:
-  explicit HElementsKind(HValue* value) : HUnaryOperation(value) {
-    set_representation(Representation::Integer32());
-    SetFlag(kUseGVN);
-    SetGVNFlag(kDependsOnElementsKind);
-  }
-
-  virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
-    return Representation::Tagged();
-  }
-
-  DECLARE_CONCRETE_INSTRUCTION(ElementsKind)
-
- protected:
-  virtual bool DataEquals(HValue* other) V8_OVERRIDE { return true; }
-
- private:
-  virtual bool IsDeletable() const V8_OVERRIDE { return true; }
-};
-
-
 class HUnaryMathOperation V8_FINAL : public HTemplateInstruction<2> {
  public:
   static HInstruction* New(Zone* zone,
                            HValue* context,
                            HValue* value,
                            BuiltinFunctionId op);
 
   HValue* context() { return OperandAt(0); }
   HValue* value() { return OperandAt(1); }
 
@@ skipping 4898 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_