diff -r e6beb62de02d -r e1162778c1c8 src/share/vm/oops/instanceKlass.hpp
--- a/src/share/vm/oops/instanceKlass.hpp	Tue Apr 05 19:14:03 2011 -0700
+++ b/src/share/vm/oops/instanceKlass.hpp	Thu Apr 07 09:53:20 2011 -0700
@@ -403,6 +403,8 @@
   ReferenceType reference_type() const     { return _reference_type; }
   void set_reference_type(ReferenceType t) { _reference_type = t; }
 
+  static int reference_type_offset_in_bytes() { return offset_of(instanceKlass, _reference_type); }
+
   // find local field, returns true if found
   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
   // find field in direct superinterfaces, returns the interface in which the field is defined