Fix windows compilation

Author: nbdd0121

src/test/run-make-fulldeps/foreign-rust-exceptions/foo.rs

@@ -1,6 +1,7 @@
 #![feature(c_unwind)]
 
-#[link(name = "bar")]
+#[cfg_attr(not(windows), link(name = "bar"))]
+#[cfg_attr(windows, link(name = "bar.dll"))]
 extern "C-unwind" {
     fn panic();
 }