Get rid of the HInstanceSize instruction.

src/mips/lithium-codegen-mips.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 2727 matching lines @@
                   instr,
                   RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
   LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
   safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
   // Put the result value into the result register slot and
   // restore all registers.
   __ StoreToSafepointRegisterSlot(result, result);
 }
 
 
-void LCodeGen::DoInstanceSize(LInstanceSize* instr) {
-  Register object = ToRegister(instr->object());
-  Register result = ToRegister(instr->result());
-  __ lw(result, FieldMemOperand(object, HeapObject::kMapOffset));
-  __ lbu(result, FieldMemOperand(result, Map::kInstanceSizeOffset));
-}
-
-
 void LCodeGen::DoCmpT(LCmpT* instr) {
   ASSERT(ToRegister(instr->context()).is(cp));
   Token::Value op = instr->op();
 
   Handle<Code> ic = CompareIC::GetUninitialized(isolate(), op);
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
   // On MIPS there is no need for a "no inlined smi code" marker (nop).
 
   Condition condition = ComputeCompareCondition(op);
   // A minor optimization that relies on LoadRoot always emitting one
@@ skipping 3082 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal