Refactor and fix polymorphic KeyedStoreIC creation

src/objects.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4252 matching lines @@
   // it had exactly zero inobject properties.
   // The "shared" flags of both this map and |other| are ignored.
   bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
 
   // Returns true if this map and |other| describe equivalent objects.
   // The "shared" flags of both this map and |other| are ignored.
   bool EquivalentTo(Map* other) {
     return EquivalentToForNormalization(other, KEEP_INOBJECT_PROPERTIES);
   }
 
+  // Returns the contents of this map's descriptor array for the given string.
+  // May return NULL. |safe_to_add_transition| is set to false and NULL
+  // is returned if adding transitions is not allowed.
+  Object* GetDescriptorContents(String* sentinel_name,
+                                bool* safe_to_add_transitions);
+
+  // Returns the map that this map transitions to if its elements_kind
+  // is changed to |elements_kind|, or NULL if no such map is cached yet.
+  // |safe_to_add_transitions| is set to false if adding transitions is not
+  // allowed.
+  Map* LookupElementsTransitionMap(ElementsKind elements_kind,
+                                   bool* safe_to_add_transition);
+
+  // Adds an entry to this map's descriptor array for a transition to
+  // |transitioned_map| when its elements_kind is changed to |elements_kind|.
+  MaybeObject* AddElementsTransition(ElementsKind elements_kind,
+                                     Map* transitioned_map);
+
   // Dispatched behavior.
 #ifdef OBJECT_PRINT
   inline void MapPrint() {
     MapPrint(stdout);
   }
   void MapPrint(FILE* out);
 #endif
 #ifdef DEBUG
   void MapVerify();
   void SharedMapVerify();
@@ skipping 97 matching lines @@
   // Layout of the default cache. It holds alternating name and code objects.
   static const int kCodeCacheEntrySize = 2;
   static const int kCodeCacheEntryNameOffset = 0;
   static const int kCodeCacheEntryCodeOffset = 1;
 
   typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
                               kPointerFieldsEndOffset,
                               kSize> BodyDescriptor;
 
  private:
+  String* elements_transition_sentinel_name();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
 };
 
 
 // An abstract superclass, a marker class really, for simple structure classes.
 // It doesn't carry much functionality but allows struct classes to be
 // identified in the type system.
 class Struct: public HeapObject {
  public:
   inline void InitializeBody(int object_size);
@@ skipping 3174 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_