Add run-pass case for issue #14308

Enum wildcard patterns in match behave wrong when applied to tuple
structs. They either ICE or cause an LLVM error.

src/test/run-pass/issue-14308.rs

@@ -0,0 +1,32 @@
+// Copyright 2014 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.
+
+struct A(int);
+struct B;
+
+fn main() {
+    let x = match A(3) {
+        A(..) => 1
+    };
+    assert_eq!(x, 1);
+    let x = match A(4) {
+        A(1) => 1,
+        A(..) => 2
+    };
+    assert_eq!(x, 2);
+
+    // This next test uses a (..) wildcard match on a nullary struct.
+    // There's no particularly good reason to support this, but it's currently allowed,
+    // and this makes sure it doesn't ICE or break LLVM.
+    let x = match B {
+        B(..) => 3
+    };
+    assert_eq!(x, 3);
+}