anchor.diff:            `(sys.lap-x86:mov64 :r8 (:r8 1 (:rcx 8))))
       (setf *r8-value* (list (gensym)))))
   
  -(defbuiltin (setf system.internals::%struct-slot) (value object slot)
  +(defbuiltin (setf system.internals::%struct-slot) (value object slot) ()
     (let ((type-error-label (gensym))
           (bounds-error-label (gensym)))
       (emit-trailer (type-error-label)
  
positive.code:           `(sys.lap-x86:mov64 :r8 (:symbol-function :r8)))
      (setf *r8-value* (list (gensym)))))
  
  (defbuiltin (setf symbol-function) (value symbol)
    (let ((symbol-type-error-label (gensym))
  	(function-type-error-label (gensym)))
      (emit-trailer (symbol-type-error-label)
  
negative.code: (define-accessor sys.int::%array-header-storage
      sys.int::%array-header #b0011 :array-header-storage)
  
  (defbuiltin null (object) ()
    (load-in-reg :r8 object t)
    (emit `(sys.lap-x86:cmp64 :r8 nil))
    (predicate-result :e))
  
  (defbuiltin not (object) ()
    (load-in-reg :r8 object t)
    (emit `(sys.lap-x86:cmp64 :r8 nil))
    (predicate-result :e))
  
  (defbuiltin eq (x y) ()
    (load-in-reg :r9 y t)
    (load-in-reg :r8 x t)
    (emit `(sys.lap-x86:cmp64 :r8 :r9))
    (predicate-result :e))
  
  (defbuiltin eql (x y) ()
    (load-in-reg :r9 y t)
    (load-in-reg :r8 x t)
    (emit `(sys.lap-x86:cmp64 :r8 :r9))
    (predicate-result :e))
  
  (defbuiltin system:io-port/8 (port) ()
    (smash-r8)
    (emit `(sys.lap-x86:xor32 :eax :eax))
    (cond ((and (consp port)
  