fix the build

Author: Oneirical

tests/run-make/reachable-extern-fn-available-lto/rmake.rs

@@ -9,15 +9,15 @@
 
 //@ ignore-cross-compile
 
-use run_make_support::{cc, extra_c_flags, run, rustc, static_lib, tmp_dir};
+use run_make_support::{cc, extra_c_flags, run, rustc, static_lib};
 
 fn main() {
     let libbar_path = static_lib("bar");
     rustc().input("foo.rs").crate_type("rlib").run();
     rustc()
         .input("bar.rs")
         .crate_type("staticlib")
-        .lto()
+        .arg("-Clto")
         .library_search_path(".")
         .output(&libbar_path)
         .run();