[crankshaft] Remove the useless HCallStub instruction.

src/crankshaft/mips/lithium-mips.cc

 // Copyright 2012 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.
 
 #include "src/crankshaft/mips/lithium-mips.h"
 
 #include <sstream>
 
 #if V8_TARGET_ARCH_MIPS
 
@@ skipping 2390 matching lines @@
     spill_index = env_index - instr->environment()->first_local_index();
     if (spill_index > LUnallocated::kMaxFixedSlotIndex) {
       Retry(kTooManySpillSlotsNeededForOSR);
       spill_index = 0;
     }
   }
   return DefineAsSpilled(new(zone()) LUnknownOSRValue, spill_index);
 }
 
 
-LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
-  LOperand* context = UseFixed(instr->context(), cp);
-  return MarkAsCall(DefineFixed(new(zone()) LCallStub(context), v0), instr);
-}
-
-
 LInstruction* LChunkBuilder::DoArgumentsObject(HArgumentsObject* instr) {
   // There are no real uses of the arguments object.
   // arguments.length and element access are supported directly on
   // stack arguments, and any real arguments object use causes a bailout.
   // So this value is never used.
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoCapturedObject(HCapturedObject* instr) {
@@ skipping 135 matching lines @@
   LOperand* function = UseRegisterAtStart(instr->function());
   LAllocateBlockContext* result =
       new(zone()) LAllocateBlockContext(context, function);
   return MarkAsCall(DefineFixed(result, cp), instr);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS