Remove the unused HElementsKind instruction.

src/arm/lithium-codegen-arm.cc

 // 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 1846 matching lines @@
 }
 
 
 void LCodeGen::DoMapEnumLength(LMapEnumLength* instr) {
   Register result = ToRegister(instr->result());
   Register map = ToRegister(instr->value());
   __ EnumLength(result, map);
 }
 
 
-void LCodeGen::DoElementsKind(LElementsKind* instr) {
-  Register result = ToRegister(instr->result());
-  Register input = ToRegister(instr->value());
-
-  // Load map into |result|.
-  __ ldr(result, FieldMemOperand(input, HeapObject::kMapOffset));
-  // Load the map's "bit field 2" into |result|. We only need the first byte,
-  // but the following bit field extraction takes care of that anyway.
-  __ ldr(result, FieldMemOperand(result, Map::kBitField2Offset));
-  // Retrieve elements_kind from bit field 2.
-  __ ubfx(result, result, Map::kElementsKindShift, Map::kElementsKindBitCount);
-}
-
-
 void LCodeGen::DoValueOf(LValueOf* instr) {
   Register input = ToRegister(instr->value());
   Register result = ToRegister(instr->result());
   Register map = ToRegister(instr->temp());
   Label done;
 
   if (!instr->hydrogen()->value()->IsHeapObject()) {
     // If the object is a smi return the object.
     __ SmiTst(input);
     __ Move(result, input, eq);
@@ skipping 3899 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal