Rollup merge of #39653 - JanZerebecki:test-issue-27433, r=alexcrichton

Add test for #27433

src/test/compile-fail/issue-27433.rs

@@ -0,0 +1,15 @@
+// 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.
+
+fn main() {
+    let foo = 42u32;
+    const FOO : u32 = foo;
+                   //~^ ERROR attempt to use a non-constant value in a constant
+}