add broken test

src/test/run-pass/mir-inlining/no-trait-method-issue-40473.rs

@@ -0,0 +1,23 @@
+// Copyright 2017 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.
+
+// compile-flags:-Zmir-opt-level=2
+pub trait Foo {
+    fn bar(&self) -> usize { 2 }
+}
+
+impl Foo for () {
+    fn bar(&self) -> usize { 3 }
+}
+
+fn main() {
+    let result = ().bar();
+    assert_eq!(result, 3);
+}