Allow hidden properties and implement GetIdentityHash

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 177 matching lines @@
   V(invalid_lhs_in_prefix_op_symbol, "invalid_lhs_in_prefix_op")         \
   V(illegal_return_symbol, "illegal_return")                             \
   V(illegal_break_symbol, "illegal_break")                               \
   V(illegal_continue_symbol, "illegal_continue")                         \
   V(unknown_label_symbol, "unknown_label")                               \
   V(redeclaration_symbol, "redeclaration")                               \
   V(failure_symbol, "<failure>")                                         \
   V(space_symbol, " ")                                                   \
   V(exec_symbol, "exec")                                                 \
   V(zero_symbol, "0")                                                    \
-  V(global_eval_symbol, "GlobalEval")
+  V(global_eval_symbol, "GlobalEval")                                    \
+  V(hidden_symbol, "...hidden...")                                       \
+  V(identity_hash_symbol, "v8::IdentityHash")
 
 
 // Forward declaration of the GCTracer class.
 class GCTracer;
 
 
 // The all static Heap captures the interface to the global object heap.
 // All JavaScript contexts by this process share the same object heap.
 
 class Heap : public AllStatic {
@@ skipping 1095 matching lines @@
   int marked_count_;
 
   // The count from the end of the previous full GC.  Will be zero if there
   // was no previous full GC.
   int previous_marked_count_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_