Fix #%app bindings for `with-contract'-based contract forms.

Closes PR11975.

collects/racket/contract/region.rkt

@@ -467,9 +467,11 @@
           (quasisyntax/loc stx
             (set! id (contract ctc arg neg pos (quote id) (quote-srcloc id))))]
          [(f arg ...)
+          (with-syntax ([app (datum->syntax stx '#%app)])
             (quasisyntax/loc stx
-            ((contract ctc id pos neg (quote id) (quote-srcloc id))
+              (app
-             arg ...))]
+               (contract ctc id pos neg (quote id) (quote-srcloc id))
+               arg ...)))]
          [ident
           (identifier? (syntax ident))
           (quasisyntax/loc stx

collects/tests/racket/contract-test.rktl

@@ -4865,6 +4865,23 @@
                           (f))])
       1))
   
+  (test/spec-passed/result
+   'with-contract-#%app
+   '(begin
+      (eval '(module app racket
+               (define-syntax (-app x) #''apped)
+               (provide (rename-out (-app #%app)))))
+      (eval '(module b racket
+               (require 'app)
+               (provide h i)
+               (with-contract x ([f any/c]) (define (f x) 'f))
+               (define (g x) 'g)
+               (define h (f 2))
+               (define i (g 2))))
+      (eval '(require 'b))
+      (eval '(list h i)))
+   (list 'apped 'apped))
+
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