Introduce a new AccessorPair type for handling JavaScript accessors.

src/factory.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 51 matching lines @@
 
   Handle<ObjectHashTable> NewObjectHashTable(int at_least_space_for);
 
   Handle<DescriptorArray> NewDescriptorArray(int number_of_descriptors);
   Handle<DeoptimizationInputData> NewDeoptimizationInputData(
       int deopt_entry_count,
       PretenureFlag pretenure);
   Handle<DeoptimizationOutputData> NewDeoptimizationOutputData(
       int deopt_entry_count,
       PretenureFlag pretenure);
+  // Allocates a pre-tenured empty AccessorPair.
+  Handle<AccessorPair> NewAccessorPair();
 
   Handle<String> LookupSymbol(Vector<const char> str);
   Handle<String> LookupSymbol(Handle<String> str);
   Handle<String> LookupAsciiSymbol(Vector<const char> str);
   Handle<String> LookupAsciiSymbol(Handle<SeqAsciiString>,
                                    int from,
                                    int length);
   Handle<String> LookupTwoByteSymbol(Vector<const uc16> str);
   Handle<String> LookupAsciiSymbol(const char* str) {
     return LookupSymbol(CStrVector(str));
@@ skipping 406 matching lines @@
   // Update the map cache in the global context with (keys, map)
   Handle<MapCache> AddToMapCache(Handle<Context> context,
                                  Handle<FixedArray> keys,
                                  Handle<Map> map);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FACTORY_H_