;; offset of next position
(next-offs 0 :type offset)
;; a sap pointing to our segment
- (segment-sap (missing-arg) :type sb!sys:system-area-pointer)
+ (segment-sap nil :type (or null sb!sys:system-area-pointer))
;; the current segment
(segment nil :type (or null segment))
;; what to align to in most cases