Add tests for lib defaults

src/test/run-pass/auxiliary/clibrary.rs

@@ -0,0 +1,15 @@
+// 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.
+
+// no-prefer-dynamic
+#![crate_type = "staticlib"]
+
+#[no_mangle]
+pub extern "C" fn foo(x:i32) -> i32 { x }

src/test/run-pass/lib-defaults.rs

@@ -0,0 +1,23 @@
+// Copyright 2017 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.
+
+// aux-build:clibrary.rs
+// compile-flags: -lclibrary
+
+#[link(name = "clibrary", kind = "static")]
+extern "C" {
+    pub fn foo(x:i32) -> i32;
+}
+
+fn main() {
+    unsafe {
+        foo(42);
+    }
+}