Reimplemented the KeyedLookupCache to speed up access.

src/objects.h

Index: src/objects.h
===================================================================
--- src/objects.h	(revision 2194)
+++ src/objects.h	(working copy)
@@ -59,7 +59,6 @@
 //             - SymbolTable
 //             - CompilationCacheTable
 //             - MapCache
-//             - LookupCache
 //           - Context
 //           - GlobalContext
 //       - String
@@ -678,7 +677,6 @@
   inline bool IsSymbolTable();
   inline bool IsCompilationCacheTable();
   inline bool IsMapCache();
-  inline bool IsLookupCache();
   inline bool IsPrimitive();
   inline bool IsGlobalObject();
   inline bool IsJSGlobalObject();
@@ -2012,27 +2010,6 @@
 };
 
 
-// LookupCache.
-//
-// Maps a key consisting of a map and a name to an index within a
-// fast-case properties array.
-//
-// LookupCaches are used to avoid repeatedly searching instance
-// descriptors.
-class LookupCache: public HashTable<0, 2> {
- public:
-  int Lookup(Map* map, String* name);
-  Object* Put(Map* map, String* name, int offset);
-  static inline LookupCache* cast(Object* obj);
-
-  // Constant returned by Lookup when the key was not found.
-  static const int kNotFound = -1;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(LookupCache);
-};
-
-
 // Dictionary for keeping properties and elements in slow case.
 //
 // One element in the prefix is used for storing non-element