Add UFCS privacy test.

src/test/compile-fail/privacy-ufcs.rs

@@ -0,0 +1,24 @@
+// Copyright 2015 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.
+
+// Test to ensure private traits are inaccessible with UFCS angle-bracket syntax.
+
+mod foo {
+    trait Bar {
+        fn baz() {}
+    }
+
+    impl Bar for i32 {}
+}
+
+fn main() {
+    <i32 as ::foo::Bar>::baz(); //~ERROR method `baz` is inaccessible
+                                //~^NOTE: trait `Bar` is private
+}