Add a TR test that I forgot to commit

Relevant to commit 18d4eb5135

pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/fail/same-type-variable-error-msg.rkt

@@ -0,0 +1,14 @@
+#;
+(exn-pred #rx"but got a different a \\(bound in another scope\\)")
+#lang typed/racket
+
+;; Test that the error message in this case mentions
+;; that the type variables look the same but are
+;; different
+
+(: f (All (a) (a -> a)))
+(define (f x)
+  (: g (All (a) (a -> a)))
+  (define (g y) x)
+  x)
+