[crankshaft] Remove the useless HCallStub instruction.

src/crankshaft/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 921 matching lines @@
 void LCodeGen::DoInstructionGap(LInstructionGap* instr) {
   DoGap(instr);
 }
 
 
 void LCodeGen::DoParameter(LParameter* instr) {
   // Nothing to do.
 }
 
 
-void LCodeGen::DoCallStub(LCallStub* instr) {
-  DCHECK(ToRegister(instr->context()).is(cp));
-  DCHECK(ToRegister(instr->result()).is(v0));
-  switch (instr->hydrogen()->major_key()) {
-    case CodeStub::RegExpExec: {
-      RegExpExecStub stub(isolate());
-      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
-      break;
-    }
-    case CodeStub::SubString: {
-      SubStringStub stub(isolate());
-      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
-      break;
-    }
-    default:
-      UNREACHABLE();
-  }
-}
-
-
 void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
   GenerateOsrPrologue();
 }
 
 
 void LCodeGen::DoModByPowerOf2I(LModByPowerOf2I* instr) {
   Register dividend = ToRegister(instr->dividend());
   int32_t divisor = instr->divisor();
   DCHECK(dividend.is(ToRegister(instr->result())));
 
@@ skipping 4601 matching lines @@
   __ Push(at, ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8