Make Dart_IdentityEqual live up to its sepc and not leak boxing implementation detail. (Reland r275…

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 3735 matching lines @@
   RawType* GetType() const;
 
   virtual RawAbstractTypeArguments* GetTypeArguments() const;
   virtual void SetTypeArguments(const AbstractTypeArguments& value) const;
 
   // Check if the type of this instance is a subtype of the given type.
   bool IsInstanceOf(const AbstractType& type,
                     const AbstractTypeArguments& type_instantiator,
                     Error* bound_error) const;
 
+  // Check whether this instance is identical to the argument according to the
+  // specification of dare:core's identical().
+  bool IsIdenticalTo(const Instance& other) const;
+
   bool IsValidNativeIndex(int index) const {
     return ((index >= 0) && (index < clazz()->ptr()->num_native_fields_));
   }
 
   inline intptr_t GetNativeField(Isolate* isolate, int index) const;
   void SetNativeField(int index, intptr_t value) const;
 
   // Returns true if the instance is a closure object.
   bool IsClosure() const;
 
@@ skipping 2410 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_