[crankshaft] Remove the useless HCallStub instruction.

src/crankshaft/x64/lithium-codegen-x64.cc

 // Copyright 2013 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/crankshaft/x64/lithium-codegen-x64.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 888 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(rsi));
-  DCHECK(ToRegister(instr->result()).is(rax));
-  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 4675 matching lines @@
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64