[turbofan] Introduce a dedicated ConvertTaggedHoleToUndefined operator.

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/operator.h"
@@ skipping 101 matching lines @@
   kNeverReturnHole,  // Never return the hole (deoptimize instead).
   kAllowReturnHole   // Allow to return the hole (signaling NaN).
 };
 
 size_t hash_value(CheckFloat64HoleMode);
 
 std::ostream& operator<<(std::ostream&, CheckFloat64HoleMode);
 
 CheckFloat64HoleMode CheckFloat64HoleModeOf(const Operator*) WARN_UNUSED_RESULT;
 
-enum class CheckTaggedHoleMode : uint8_t {
-  kNeverReturnHole,        // Never return the hole (deoptimize instead).
-  kConvertHoleToUndefined  // Convert the hole to undefined.
-};
-
-size_t hash_value(CheckTaggedHoleMode);
-
-std::ostream& operator<<(std::ostream&, CheckTaggedHoleMode);
-
-CheckTaggedHoleMode CheckTaggedHoleModeOf(const Operator*) WARN_UNUSED_RESULT;
-
 enum class CheckTaggedInputMode : uint8_t {
   kNumber,
   kNumberOrOddball,
 };
 
 size_t hash_value(CheckTaggedInputMode);
 
 std::ostream& operator<<(std::ostream&, CheckTaggedInputMode);
 
 CheckTaggedInputMode CheckTaggedInputModeOf(const Operator*) WARN_UNUSED_RESULT;
@@ skipping 189 matching lines @@
   const Operator* CheckedUint32Mod();
   const Operator* CheckedInt32Mul(CheckForMinusZeroMode);
   const Operator* CheckedUint32ToInt32();
   const Operator* CheckedFloat64ToInt32(CheckForMinusZeroMode);
   const Operator* CheckedTaggedSignedToInt32();
   const Operator* CheckedTaggedToInt32(CheckForMinusZeroMode);
   const Operator* CheckedTaggedToFloat64(CheckTaggedInputMode);
   const Operator* CheckedTruncateTaggedToWord32();
 
   const Operator* CheckFloat64Hole(CheckFloat64HoleMode);
-  const Operator* CheckTaggedHole(CheckTaggedHoleMode);
+  const Operator* CheckTaggedHole();
+  const Operator* ConvertTaggedHoleToUndefined();
 
   const Operator* ObjectIsCallable();
   const Operator* ObjectIsNumber();
   const Operator* ObjectIsReceiver();
   const Operator* ObjectIsSmi();
   const Operator* ObjectIsString();
   const Operator* ObjectIsUndetectable();
 
   // ensure-writable-fast-elements object, elements
   const Operator* EnsureWritableFastElements();
@@ skipping 34 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(SimplifiedOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SIMPLIFIED_OPERATOR_H_