Fix the use of closures within #[panic_implementation]

src/test/compile-fail/panic_implementation-closures.rs

@@ -0,0 +1,21 @@
+// Copyright 2018 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-pass
+
+#![crate_type = "rlib"]
+#![no_std]
+#![feature(panic_implementation)]
+
+#[panic_implementation]
+pub fn panic_fmt(_: &::core::panic::PanicInfo) -> ! {
+    |x: u8| x;
+    loop {}
+}