error: expected one of `extern`, `fn`, or `unsafe`, found keyword `const`
  --> $DIR/no-async-const.rs:4:11
   |
LL | pub async const fn x() {}
   |     ------^^^^^
   |     |     |
   |     |     expected one of `extern`, `fn`, or `unsafe`
   |     help: `const` must come before `async`: `const async`
   |
   = note: keyword order for functions declaration is `pub`, `default`, `const`, `async`, `unsafe`, `extern`

error: aborting due to previous error