Revert 428. Breaks 64-bit compilation.

src/heap.cc

 // 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 2332 matching lines @@
 #undef ROOT_ITERATE
   SYNCHRONIZE_TAG("strong_root_list");
 
 #define STRUCT_MAP_ITERATE(NAME, Name, name) \
   v->VisitPointer(reinterpret_cast<Object**>(&name##_map_));
   STRUCT_LIST(STRUCT_MAP_ITERATE);
 #undef STRUCT_MAP_ITERATE
   SYNCHRONIZE_TAG("struct_map");
 
 #define SYMBOL_ITERATE(name, string) \
-  v->VisitPointer(bit_cast<Object**, String**>(&name##_));
+  v->VisitPointer(reinterpret_cast<Object**>(&name##_));
   SYMBOL_LIST(SYMBOL_ITERATE)
 #undef SYMBOL_ITERATE
   SYNCHRONIZE_TAG("symbol");
 
   Bootstrapper::Iterate(v);
   SYNCHRONIZE_TAG("bootstrapper");
   Top::Iterate(v);
   SYNCHRONIZE_TAG("top");
   Debug::Iterate(v);
   SYNCHRONIZE_TAG("debug");
@@ skipping 671 matching lines @@
       return "Scavenge";
     case MARK_COMPACTOR:
       return MarkCompactCollector::HasCompacted() ? "Mark-compact"
                                                   : "Mark-sweep";
   }
   return "Unknown GC";
 }
 
 
 } }  // namespace v8::internal