Add runtime function for string to array conversion.

src/heap.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 432 matching lines @@
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
   // failed.
   // Please note this does not perform a garbage collection.
   static Object* AllocateJSGlobalPropertyCell(Object* value);
 
   // Allocates a fixed array initialized with undefined values
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
   // failed.
   // Please note this does not perform a garbage collection.
   static Object* AllocateFixedArray(int length, PretenureFlag pretenure);
-  // Allocate uninitialized, non-tenured fixed array with length elements.
+  // Allocates a fixed array initialized with undefined values
   static Object* AllocateFixedArray(int length);
 
+  // Allocates an uninitialized fixed array. It must be filled by the caller.
+  //
+  // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
+  // failed.
+  // Please note this does not perform a garbage collection.
+  static Object* AllocateUninitializedFixedArray(int length);
+
   // Make a copy of src and return it. Returns
   // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed.
   static Object* CopyFixedArray(FixedArray* src);
 
   // Allocates a fixed array initialized with the hole values.
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
   // failed.
   // Please note this does not perform a garbage collection.
   static Object* AllocateFixedArrayWithHoles(int length);
 
@@ skipping 1263 matching lines @@
 
   // To speed up scavenge collections new space string are kept
   // separate from old space strings.
   static List<Object*> new_space_strings_;
   static List<Object*> old_space_strings_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_