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`.