Mir typeck Cast for ClosureFnPtr value

src/test/compile-fail/mir_check_cast_closure.rs

@@ -0,0 +1,22 @@
+// 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: -Z borrowck=mir -Z nll
+
+#![allow(dead_code)]
+
+fn bar<'a, 'b>() -> fn(&'a u32, &'b u32) -> &'a u32 {
+    let g: fn(_, _) -> _ = |_x, y| y;
+    g
+    //~^ WARNING not reporting region error due to -Znll
+    //~| ERROR free region `'b` does not outlive free region `'a`
+}
+
+fn main() {}