Do not follow accessor map transitions when marking descriptor arrays.

src/mark-compact.h

 // Copyright 2012 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 627 matching lines @@
 
   // Creates back pointers for all map transitions, stores them in
   // the prototype field.  The original prototype pointers are restored
   // in ClearNonLiveTransitions().  All JSObject maps
   // connected by map transitions have the same prototype object, which
   // is why we can use this field temporarily for back pointers.
   void CreateBackPointers();
 
   // Mark a Map and its DescriptorArray together, skipping transitions.
   void MarkMapContents(Map* map);
+  bool MarkUnmarked(Object* value);
+  bool MarkUnmarkedAndPush(Object* value);
+  void MarkAccessorPairSlot(AccessorPair* accessors, int offset);
   void MarkDescriptorArray(DescriptorArray* descriptors);
 
   // Mark the heap roots and all objects reachable from them.
   void MarkRoots(RootMarkingVisitor* visitor);
 
   // Mark the symbol table specially.  References to symbols from the
   // symbol table are weak.
   void MarkSymbolTable();
 
   // Mark objects in object groups that have at least one object in the
@@ skipping 95 matching lines @@
 
   friend class Heap;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_H_