error[E0658]: `async` blocks are not allowed in constants
  --> $DIR/const-suggest-feature.rs:5:13
   |
LL |     let x = async { 13 };
   |             ^^^^^^^^^^^^
   |
   = note: see issue #85368 <https://github.com/rust-lang/rust/issues/85368> for more information
   = help: add `#![feature(const_async_blocks)]` to the crate attributes to enable
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0658`.