Add test

Author: Manishearth

src/test/run-make-fulldeps/extern-prelude/Makefile

@@ -7,5 +7,6 @@ all:
 	$(RUSTC) basic.rs --extern ep_lib=$(TMPDIR)/libep_lib.rlib
 	$(RUSTC) shadow-mod.rs --extern ep_lib=$(TMPDIR)/libep_lib.rlib
 	$(RUSTC) shadow-prelude.rs --extern Vec=$(TMPDIR)/libep_vec.rlib
+	$(RUSTC) inner-mod.rs --extern S=$(TMPDIR)/libep_vec.rlib --extern ep_lib=$(TMPDIR)/libep_lib.rlib
 	$(RUSTC) relative-only.rs --extern ep_lib=$(TMPDIR)/libep_lib.rlib 2>&1 | $(CGREP) "unresolved import"
 	$(RUSTC) relative-only.rs --extern ep_lib=$(TMPDIR)/libep_lib.rlib 2>&1 | $(CGREP) "failed to resolve"

src/test/run-make-fulldeps/extern-prelude/inner-mod.rs

@@ -0,0 +1,17 @@
+// Copyright 2018 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.
+
+// Modules that clash with crates don't hit feature errors when
+// the feature is disabled
+
+fn main() {
+    let s = ep_lib::S;
+    s.internal(); // OK
+}