scrutiny for list-of type wrong when matched with pair types

[sjamaan]

See the program in #948; this particular case was fixed, but changing list to cons will cause breakage:

(: apply1 (forall ((a number) b) (procedure ((procedure (#!rest a) b) (list-of a)) b)))

(define (apply1 f args)
  (apply f args))

(apply1 + (cons 'a (cons 2 '())))  ;;; Should give a warning, but doesn't

[sjamaan]

Fixed with dd46f23