Copy-on-write arrays.

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 37 matching lines @@
   /* Cluster the most popular ones in a few cache lines here at the top.    */ \
   V(Smi, stack_limit, StackLimit)                                              \
   V(Object, undefined_value, UndefinedValue)                                   \
   V(Object, the_hole_value, TheHoleValue)                                      \
   V(Object, null_value, NullValue)                                             \
   V(Object, true_value, TrueValue)                                             \
   V(Object, false_value, FalseValue)                                           \
   V(Map, heap_number_map, HeapNumberMap)                                       \
   V(Map, global_context_map, GlobalContextMap)                                 \
   V(Map, fixed_array_map, FixedArrayMap)                                       \
+  V(Map, fixed_cow_array_map, FixedCOWArrayMap)                                \
   V(Object, no_interceptor_result_sentinel, NoInterceptorResultSentinel)       \
   V(Map, meta_map, MetaMap)                                                    \
   V(Object, termination_exception, TerminationException)                       \
   V(Map, hash_table_map, HashTableMap)                                         \
   V(FixedArray, empty_fixed_array, EmptyFixedArray)                            \
   V(Map, string_map, StringMap)                                                \
   V(Map, ascii_string_map, AsciiStringMap)                                     \
   V(Map, symbol_map, SymbolMap)                                                \
   V(Map, ascii_symbol_map, AsciiSymbolMap)                                     \
   V(Map, cons_symbol_map, ConsSymbolMap)                                       \
@@ skipping 1911 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_