error: expected `fn`, found keyword `unsafe`
  --> $DIR/issue-19398.rs:2:19
   |
LL |     extern "Rust" unsafe fn foo();
   |     --------------^^^^^^
   |     |             |
   |     |             expected `fn`
   |     help: `unsafe` must come before `extern "Rust"`: `unsafe extern "Rust"`
   |
   = note: keyword order for functions declaration is `pub`, `default`, `const`, `async`, `unsafe`, `extern`

error: aborting due to 1 previous error