Fix broken case in case-lambda.

pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-lambda-unit.rkt

@@ -317,7 +317,7 @@
       [(Function: (and fs (list (arr: argss rets rests drests '()) ...)))
        (for/list ([a (in-list argss)] [f (in-list fs)]  [r (in-list rests)] [dr (in-list drests)]
                   #:when (if (formals-rest fml)
-                             (>= (length a) (length (formals-positional fml)))
+                             (or r (>= (length a) (length (formals-positional fml))))
                              ((if (or r dr) <= =) (length a) (length (formals-positional fml)))))
          f)]
       [_ null]))

pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/fail/case-lambda1.rkt

@@ -1,5 +1,5 @@
 #;
-(exn-pred 1)
+(exn-pred 2)
 #lang typed/racket
 (: f (case->
   (Symbol Symbol *  -> Integer)

pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/typecheck-tests.rkt

@@ -2747,6 +2747,18 @@
            (f 1 2 3))
          #:ret (ret Univ -true-filter)]
 
+       [tc-err
+         (case-lambda
+           ((x y . z) 'x)
+           ((x . y) 'x)
+           (w (first w)))
+         #:ret
+           (ret (cl->* (->* (list -Symbol -Symbol) -Symbol -Symbol)
+                       (->* (list) -String -String)))
+         #:expected
+           (ret (cl->* (->* (list -Symbol -Symbol) -Symbol -Symbol)
+                       (->* (list) -String -String)))]
+
        ;; typecheck-fail should fail
        [tc-err (typecheck-fail #'stx "typecheck-fail")
                #:msg #rx"typecheck-fail"]