remove unnecessary feature gate

Author: KodrAus

compiletest/src/lib.rs

@@ -6,8 +6,6 @@ under a different crate name so that can be imported in the compile tests.
 This currently appears to use the right local build of `lazy_static`.
 */
 
-#![feature(use_extern_macros)]
-
 extern crate lazy_static;
 
 pub use self::lazy_static::*;