error[E0658]: intrinsics are subject to change --> $DIR/feature-gated-feature-in-macro-arg.rs:18:9 | LL | / extern "rust-intrinsic" { //~ ERROR intrinsics are subject to change LL | | fn atomic_fence(); LL | | } | |_________^ | = help: add #![feature(intrinsics)] to the crate attributes to enable error: aborting due to previous error For more information about this error, try `rustc --explain E0658`.