[turbofan] Introduce a TransitionElementsKind simplified operator.

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 263 matching lines @@
   V(LoadBuffer)                       \
   V(LoadElement)                      \
   V(StoreField)                       \
   V(StoreBuffer)                      \
   V(StoreElement)                     \
   V(ObjectIsCallable)                 \
   V(ObjectIsNumber)                   \
   V(ObjectIsReceiver)                 \
   V(ObjectIsSmi)                      \
   V(ObjectIsString)                   \
-  V(ObjectIsUndetectable)
+  V(ObjectIsUndetectable)             \
+  V(TransitionElementsKind)
 
 #define SIMPLIFIED_OP_LIST(V)      \
   SIMPLIFIED_CHANGE_OP_LIST(V)     \
   SIMPLIFIED_CHECKED_OP_LIST(V)    \
   SIMPLIFIED_COMPARE_BINOP_LIST(V) \
   SIMPLIFIED_OTHER_OP_LIST(V)
 
 // Opcodes for Machine-level operators.
 #define MACHINE_COMPARE_BINOP_LIST(V) \
   V(Word32Equal)                      \
@@ skipping 426 matching lines @@
   }
 };
 
 std::ostream& operator<<(std::ostream&, IrOpcode::Value);
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_OPCODES_H_