error: expected one of `extern` or `fn`, found keyword `async`
  --> $DIR/no-unsafe-async.rs:7:12
   |
LL | impl S {
   |        - while parsing this item list starting here
LL |     #[cfg(FALSE)]
LL |     unsafe async fn g() {}
   |            ^^^^^ expected one of `extern` or `fn`
LL | }
   | - the item list ends here

error: expected one of `extern` or `fn`, found keyword `async`
  --> $DIR/no-unsafe-async.rs:11:8
   |
LL | unsafe async fn f() {}
   |        ^^^^^ expected one of `extern` or `fn`

error: aborting due to 2 previous errors