try to remove cp and cd

Author: Oneirical

tests/run-make/bare-outfile/rmake.rs

@@ -8,8 +8,6 @@ use std::env;
 use std::fs;
 
 fn main() {
-    fs::copy("foo.rs", tmp_dir().join("foo.rs")).unwrap();
-    env::set_current_dir(tmp_dir());
     rustc().output("foo").input("foo.rs").run();
     run("foo");
 }