Fix send on a receiver with recursive type

Thanks to Matthias for finding the bug

typed-racket-lib/typed-racket/typecheck/tc-send.rkt

@@ -49,7 +49,9 @@
           "send: type mismatch"
           "expected" "an object"
           "given" rcvr-type)]))
-  (define final-ret (do-check (tc-expr/t rcvr)))
+  ;; Make sure to resolve before `do-check` because the type might
+  ;; be a Name type or recursive type and thus unable to match Instance:
+  (define final-ret (do-check (resolve (tc-expr/t rcvr))))
   (add-typeof-expr form final-ret)
   final-ret)
 

typed-racket-test/unit-tests/class-tests.rkt

@@ -2083,4 +2083,14 @@
                 (: get-a (-> String))
                 (define/public (get-a) a)))
             (error "foo"))
-          #:msg #rx"expected: String.*given: Integer"]))
+          #:msg #rx"expected: String.*given: Integer"]
+  ;; Make sure `send` works on a recursively typed object
+  [tc-e (let ()
+          (: o (Rec X (Object [m (-> Void)] [n (-> X Void)])))
+          (define o
+            (make-object (class object%
+                           (super-new)
+                           (define/public (m) (void))
+                           (define/public (n x) (void)))))
+          (send o m))
+        -Void]))