Add duplicate test

Author: GuillaumeGomez

src/test/rustdoc/remove-duplicates.rs

@@ -0,0 +1,24 @@
+// Copyright 2016 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.
+
+#![crate_name = "foo"]
+
+mod foo {
+    pub use bar::*;
+    pub mod bar {
+        pub trait Foo {
+            fn foo();
+        }
+    }
+}
+
+// @count foo/index.html '//*[@class="trait"]' 1
+pub use foo::bar::*;
+pub use foo::*;