Translate Value types to ctcs with better names

e.g., True -> '#t  instead of
      True -> "#t" for a flat-named-contract

collects/tests/typed-racket/fail/flat-contract-name.rkt

@@ -0,0 +1,14 @@
+#;
+(exn-pred #rx"expected: 0")
+
+#lang racket
+
+;; The purpose of this test is to make sure that contract
+;; errors for (Value x) types print in a good way
+
+(module a typed/racket
+  (define: (f [x : Zero]) : Zero x)
+  (provide f))
+
+(require 'a)
+(f "foo")

collects/typed-racket/private/type-contract.rkt

@@ -422,7 +422,7 @@
         [(Syntax: (Base: 'Symbol _ _ _ _)) #'identifier?]
         [(Syntax: t)
          #`(syntax/c #,(t->c t #:kind flat-sym))]
-        [(Value: v) #`(flat-named-contract #,(format "~a" v) (lambda (x) (equal? x '#,v)))]
+        [(Value: v) #`(flat-named-contract '#,v (lambda (x) (equal? x '#,v)))]
         ;; TODO Is this sound?
 	[(Param: in out) 
 	 (set-impersonator!)