Type warning in internally generated code from integer builtins

[Paul F. Dietz]

(lambda (c)
   (max
    (ceiling
     (truncate 65527
      (min -78
       (if c
           -913097464
           5)))
     (max 39 0))))

==>

; in: LAMBDA (C)
; (CEILING
; (TRUNCATE 65527
; (MIN -78
; (IF CL-TEST::C
; -913097464
; 5)))
; (MAX 39 0))
;
; caught WARNING:
; Derived type of (+ SB-C::TRU 1) is
; (VALUES (OR (INTEGER 1 1) (INTEGER -20 -20)) &OPTIONAL),
; conflicting with its asserted type
; (INTEGER 337 337).
; See also:
; The SBCL Manual, Node "Handling of Types"
;
; compilation unit finished
; caught 1 WARNING condition
#<FUNCTION (LAMBDA (C)) {53A7872B}>