Regression test for #20261

Closes #20261.

src/test/compile-fail/issue-20261.rs

@@ -0,0 +1,17 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    for (ref i,) in [].iter() { //~ ERROR: type mismatch resolving
+        i.clone();
+        //~^ ERROR: the type of this value must be known in this context
+        //~| ERROR: reached the recursion limit while auto-dereferencing
+    }
+}