test: Add a test for fixed issue #11844

Closes #11844

Author: alexcrichton

src/test/compile-fail/issue-11844.rs

@@ -0,0 +1,19 @@
+// Copyright 2014 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() {
+    let a = Some(box 1);
+    match a {
+        Ok(a) => //~ ERROR: mismatched types
+            println!("{}",a), //~ ERROR: failed to find an implementation of trait
+        None => fail!()
+    }
+}
+