Expend printing fuel in all branches

This makes (:type (Number -> Integer)) produce
(Number -> Integer) instead of expanding at the first name.
Combined with expansion cues, this makes it easier for users
to expand the relevant parts of types.

collects/tests/typed-racket/succeed/type-printer-single-level.rkt

@@ -19,6 +19,7 @@
 
 (tr-eval '(:type Foo))
 (tr-eval '(:type Bar))
+(tr-eval '(:type (Number -> Integer)))
 
 ;; if #:verbose, make sure it's the full type
 (tr-eval '(:type #:verbose Bar))
@@ -26,6 +27,7 @@
 (check-equal? (get-output-string out)
               (string-append "(U Integer String)\n[can expand further: String Integer]"
                              "(Foo -> Foo)\n[can expand further: Foo]"
+                             "(Number -> Integer)\n[can expand further: Integer Number]"
                              "((U 0 1 Byte-Larger-Than-One Positive-Index-Not-Byte "
                              "Positive-Fixnum-Not-Index Negative-Fixnum "
                              "Positive-Integer-Not-Fixnum Negative-Integer-Not-Fixnum String) "

collects/typed-racket/types/printer.rkt

@@ -235,7 +235,10 @@
 ;; print out a type
 ;; print-type : Type Port Boolean -> Void
 (define (print-type type port write? [ignored-names '()])
-  (define (fp . args) (apply fprintf port args))
+  (define (fp . args)
+    (parameterize ([current-print-type-fuel
+                    (sub1 (current-print-type-fuel))])
+      (apply fprintf port args)))
   (define (tuple? t)
     (match t
       [(Pair: a (? tuple?)) #t]
@@ -302,7 +305,12 @@
      (when proc
        (fp " ~a" proc))
      (fp ")")]
-    [(Function: arities) (fp "~a" (print-case-lambda type))]
+    [(Function: arities)
+     (define fun-type
+       (parameterize ([current-print-type-fuel
+                       (sub1 (current-print-type-fuel))])
+         (print-case-lambda type)))
+     (fp "~a" fun-type)]
     [(arr: _ _ _ _ _) (fp "(arr ~a)" (format-arr type))]
     [(Vector: e) (fp "(Vectorof ~a)" e)]
     [(HeterogeneousVector: e) (fp "(Vector")