[turbofan] Introduce CheckUnless.

src/compiler/opcodes.h

 // 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.
 
 #ifndef V8_COMPILER_OPCODES_H_
 #define V8_COMPILER_OPCODES_H_
 
 #include <iosfwd>
 
 // Opcodes for control operators.
@@ skipping 224 matching lines @@
   V(ChangeTaggedToBit)                \
   V(ChangeBitToTagged)                \
   V(CheckBounds)                      \
   V(CheckedUint32ToInt32)             \
   V(CheckedFloat64ToInt32)            \
   V(CheckedTaggedToInt32)             \
   V(CheckedTaggedToFloat64)           \
   V(CheckFloat64Hole)                 \
   V(CheckTaggedHole)                  \
   V(CheckIf)                          \
+  V(CheckUnless)                      \
   V(TruncateTaggedToWord32)           \
   V(TruncateTaggedToFloat64)          \
   V(Allocate)                         \
   V(LoadField)                        \
   V(LoadBuffer)                       \
   V(LoadElement)                      \
   V(StoreField)                       \
   V(StoreBuffer)                      \
   V(StoreElement)                     \
   V(ObjectIsCallable)                 \
@@ skipping 426 matching lines @@
   }
 };
 
 std::ostream& operator<<(std::ostream&, IrOpcode::Value);
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_OPCODES_H_