[turbofan] Address the useless overflow bit materialization.

src/compiler/simplified-operator.h

 // Copyright 2014 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.
 
 #ifndef V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 #define V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 
 #include <iosfwd>
 
 #include "src/compiler/type-hints.h"
@@ skipping 222 matching lines @@
   const Operator* ChangeFloat64ToTagged();
   const Operator* ChangeTaggedToBit();
   const Operator* ChangeBitToTagged();
   const Operator* TruncateTaggedToWord32();
   const Operator* TruncateTaggedToFloat64();
 
   const Operator* CheckBounds();
   const Operator* CheckTaggedPointer();
   const Operator* CheckTaggedSigned();
 
+  const Operator* CheckedInt32Add();
+  const Operator* CheckedInt32Sub();
   const Operator* CheckedUint32ToInt32();
   const Operator* CheckedFloat64ToInt32();
   const Operator* CheckedTaggedToInt32();
   const Operator* CheckedTaggedToFloat64();
 
   const Operator* CheckFloat64Hole(CheckFloat64HoleMode);
   const Operator* CheckTaggedHole(CheckTaggedHoleMode);
-  const Operator* CheckIf();
 
   const Operator* ObjectIsCallable();
   const Operator* ObjectIsNumber();
   const Operator* ObjectIsReceiver();
   const Operator* ObjectIsSmi();
   const Operator* ObjectIsString();
   const Operator* ObjectIsUndetectable();
 
   const Operator* TypeGuard(Type* type);
 
@@ skipping 21 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(SimplifiedOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SIMPLIFIED_OPERATOR_H_