[turbofan] Introduce a TransitionElementsKind simplified operator.

src/elements.h

 // Copyright 2012 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_ELEMENTS_H_
 #define V8_ELEMENTS_H_
 
 #include "src/elements-kind.h"
 #include "src/heap/heap.h"
 #include "src/isolate.h"
@@ skipping 92 matching lines @@
       Handle<JSObject> object, Handle<FixedArray> keys,
       GetKeysConversion convert, PropertyFilter filter = ALL_PROPERTIES) {
     return PrependElementIndices(object, handle(object->elements()), keys,
                                  convert, filter);
   }
 
   virtual void AddElementsToKeyAccumulator(Handle<JSObject> receiver,
                                            KeyAccumulator* accumulator,
                                            AddKeyConversion convert) = 0;
 
+  virtual void TransitionElementsKind(Handle<JSObject> object,
+                                      Handle<Map> map) = 0;
   virtual void GrowCapacityAndConvert(Handle<JSObject> object,
                                       uint32_t capacity) = 0;
 
   static void InitializeOncePerProcess();
   static void TearDown();
 
   virtual void Set(Handle<JSObject> holder, uint32_t entry, Object* value) = 0;
 
   virtual void Reconfigure(Handle<JSObject> object,
                            Handle<FixedArrayBase> backing_store, uint32_t entry,
@@ skipping 64 matching lines @@
                      bool allow_appending = false);
 
 MUST_USE_RESULT MaybeHandle<Object> ArrayConstructInitializeElements(
     Handle<JSArray> array,
     Arguments* args);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ELEMENTS_H_