Rollup merge of #39197 - michaelwoerister:test-38942, r=alexcrichton

Add regression test for issue #38942

Closes #38942.

Kudos to @pnkfelix and @nagisa, who did all the hard work of creating a reduced test case.

src/test/run-pass/issue-38942.rs

@@ -0,0 +1,26 @@
+// 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.
+
+// See https://github.com/rust-lang/rust/issues/38942
+
+#[repr(u64)]
+pub enum NSEventType {
+    NSEventTypePressure,
+}
+
+pub const A: u64 = NSEventType::NSEventTypePressure as u64;
+
+fn banana() -> u64 {
+    A
+}
+
+fn main() {
+    println!("banana! {}", banana());
+}