update vector ics to handle megamorphic keyed loads

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/checks.h"
@@ skipping 157 matching lines @@
 
   // The object that indicates an uninitialized cache.
   static inline Handle<Object> UninitializedSentinel(Isolate* isolate);
 
   // The object that indicates a megamorphic state.
   static inline Handle<Object> MegamorphicSentinel(Isolate* isolate);
 
   // The object that indicates a premonomorphic state.
   static inline Handle<Object> PremonomorphicSentinel(Isolate* isolate);
 
-  // The object that indicates a generic state.
-  static inline Handle<Object> GenericSentinel(Isolate* isolate);
-
   // The object that indicates a monomorphic state of Array with
   // ElementsKind
   static inline Handle<Object> MonomorphicArraySentinel(
       Isolate* isolate, ElementsKind elements_kind);
 
   // A raw version of the uninitialized sentinel that's safe to read during
   // garbage collection (e.g., for patching the cache).
   static inline Object* RawUninitializedSentinel(Heap* heap);
 
  private:
@@ skipping 150 matching lines @@
       : FeedbackNexus(vector, slot) {
     DCHECK(vector->GetKind(slot) == Code::KEYED_LOAD_IC);
   }
   KeyedLoadICNexus(TypeFeedbackVector* vector, FeedbackVectorICSlot slot)
       : FeedbackNexus(vector, slot) {
     DCHECK(vector->GetKind(slot) == Code::KEYED_LOAD_IC);
   }
 
   void Clear(Code* host);
 
-  void ConfigureGeneric();
+  void ConfigureMegamorphic();
   void ConfigurePremonomorphic();
   // name can be a null handle for element loads.
   void ConfigureMonomorphic(Handle<Name> name, Handle<HeapType> type,
                             Handle<Code> handler);
   // name can be null.
   void ConfigurePolymorphic(Handle<Name> name, TypeHandleList* types,
                             CodeHandleList* handlers);
 
   InlineCacheState StateFromFeedback() const OVERRIDE;
   int ExtractMaps(MapHandleList* maps) const OVERRIDE;
   MaybeHandle<Code> FindHandlerForMap(Handle<Map> map) const OVERRIDE;
   virtual bool FindHandlers(CodeHandleList* code_list,
                             int length = -1) const OVERRIDE;
   Name* FindFirstName() const OVERRIDE;
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_TRANSITIONS_H_