Faster moving FixedArray elements around.

src/objects.h

 // Copyright 2006-2009 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 1608 matching lines @@
   // Setter that doesn't need write barrier).
   inline void set(int index, Smi* value);
   // Setter with explicit barrier mode.
   inline void set(int index, Object* value, WriteBarrierMode mode);
 
   // Setters for frequently used oddballs located in old space.
   inline void set_undefined(int index);
   inline void set_null(int index);
   inline void set_the_hole(int index);
 
+  // Gives access to raw memory which stores the array's data.
+  inline Object** data_start();
+
   // Copy operations.
   inline Object* Copy();
   Object* CopySize(int new_length);
 
   // Add the elements of a JSArray to this FixedArray.
   Object* AddKeysFromJSArray(JSArray* array);
 
   // Compute the union of this and other.
   Object* UnionOfKeys(FixedArray* other);
 
@@ skipping 3337 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_