(make-instance 'one-slot-subclass :b b))
(compile 'make-one-slot-subclass)
-(defmethod update-instance-for-redifined-class
+(defmethod update-instance-for-redefined-class
((object one-slot-superclass) added discarded plist &rest initargs)
(declare (ignore initargs))
(error "Called U-I-F-R-C on ~A" object))