Add a test case for the preceding changes.

This would have failed on 32-to-64-bit cross-compiles.

src/test/run-pass/enum-discrim-width-stuff.rs

@@ -0,0 +1,25 @@
+// Copyright 2013 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.
+
+use std::sys;
+
+pub fn main() {
+    enum E { V = 0x1717171717171717 }
+    static C: E = V;
+    let expected: u64 = if sys::size_of::<uint>() < 8 {
+        0x17171717
+    } else {
+        0x1717171717171717
+    };
+    assert_eq!(expected, V as u64);
+    assert_eq!(expected, C as u64);
+    assert_eq!(fmt!("%?", V), ~"V");
+    assert_eq!(fmt!("%?", C), ~"V");
+}