Use vector-immutableof' and box-immutable/c' to handle boxes and vectors.

svn: r15199

original commit: cfd65e7fa2ec01f345c6092c308c6894557dc7b6

collects/tests/typed-scheme/succeed/provide-sexp.ss

@@ -0,0 +1,11 @@
+
+#lang scheme/load
+
+(module m typed-scheme
+ (provide f)
+ (: f Sexp)
+ (define f 5))
+
+(require 'm)
+
+f

collects/typed-scheme/private/type-contract.ss

@@ -93,7 +93,9 @@
 	     [(list e) e]
 	     [l #`(case-> #,@l)]))]
         [(Vector: t)
-         #`(vectorof #,(t->c t))]
+         #`(vector-immutableof #,(t->c t))]
+        [(Box: t)
+         #`(box-immutable/c #,(t->c t))]
         [(Pair: t1 t2)
          #`(cons/c #,(t->c t1) #,(t->c t2))]
         [(Opaque: p? cert)