;; this punning with MAKE-LISP-OBJ depends for its safety on
;; the frame pointer being a lispobj-aligned integer. While
;; it is, then MAKE-LISP-OBJ will always return a FIXNUM, so
;; this punning with MAKE-LISP-OBJ depends for its safety on
;; the frame pointer being a lispobj-aligned integer. While
;; it is, then MAKE-LISP-OBJ will always return a FIXNUM, so