[type-feedback-vector] Delete unused DiffersFrom().

src/type-feedback-vector.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_TYPE_FEEDBACK_VECTOR_H_
 #define V8_TYPE_FEEDBACK_VECTOR_H_
 
 #include <vector>
 
 #include "src/base/logging.h"
@@ skipping 200 matching lines @@
   static inline TypeFeedbackMetadata* cast(Object* obj);
 
   static const int kSlotsCountIndex = 0;
   static const int kReservedIndexCount = 1;
 
   // Returns number of feedback vector elements used by given slot kind.
   static inline int GetSlotSize(FeedbackVectorSlotKind kind);
 
   bool SpecDiffersFrom(const FeedbackVectorSpec* other_spec) const;
 
-  bool DiffersFrom(const TypeFeedbackMetadata* other_metadata) const;
-
   inline bool is_empty() const;
 
   // Returns number of slots in the vector.
   inline int slot_count() const;
 
   // Returns slot kind for given slot.
   FeedbackVectorSlotKind GetKind(FeedbackVectorSlot slot) const;
 
   template <typename Spec>
   static Handle<TypeFeedbackMetadata> New(Isolate* isolate, const Spec* spec);
@@ skipping 513 matching lines @@
   InlineCacheState StateFromFeedback() const override;
 };
 
 inline BinaryOperationHint BinaryOperationHintFromFeedback(int type_feedback);
 inline CompareOperationHint CompareOperationHintFromFeedback(int type_feedback);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TRANSITIONS_H_