testsuite: Add test for rust-lang#5248, closes rust-lang#5248

Author: catamorphism

src/test/run-pass/issue-5248.rs

@@ -0,0 +1,22 @@
+// 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.
+
+pub mod foo {
+    pub fn bar() { }
+}
+
+mod baz {
+    use super::foo;
+    fn main() {
+        foo::bar();
+    }
+}
+
+fn main() {}