Allow inline caching for getting the length of string wrapper objects.

src/objects.h

 // Copyright 2006-2008 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 608 matching lines @@
   inline bool IsMap();
   inline bool IsFixedArray();
   inline bool IsDescriptorArray();
   inline bool IsContext();
   inline bool IsGlobalContext();
   inline bool IsJSFunction();
   inline bool IsCode();
   inline bool IsOddball();
   inline bool IsSharedFunctionInfo();
   inline bool IsJSValue();
+  inline bool IsStringWrapper();
   inline bool IsProxy();
   inline bool IsBoolean();
   inline bool IsJSArray();
   inline bool IsJSRegExp();
   inline bool IsHashTable();
   inline bool IsDictionary();
   inline bool IsSymbolTable();
   inline bool IsCompilationCacheTable();
   inline bool IsMapCache();
   inline bool IsLookupCache();
@@ skipping 3481 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_