Add test for #30089

Author: jseyfried

src/test/compile-fail/no-extern-crate-in-glob-import.rs

@@ -0,0 +1,22 @@
+// 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.
+
+// Check that extern crate declarations are excluded from glob imports.
+
+#![feature(core)]
+extern crate core;
+
+mod T {
+    use super::*;
+}
+
+fn main() {
+    use T::core; //~ ERROR unresolved import `T::core`
+}