ices/101940.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#101940

pub trait Trait {
    type Fut<'a> where Self: 'a;
    fn fun<'a, 'b>(&'a self, x: &'_ mut &'b ()) -> Self::Fut<'a>
    where
        'b: 'a;
}
impl Trait for () {
    type Fut<'a> = impl ::std::future::Future + 'a
    where
        Self: 'a;
    fn fun<'a, 'b>(&'a self, x: &'_ mut &'b ()) -> Self::Fut<'a>
    where
        'b: 'a,
    {
        async { }
    }
}

pub fn main() {}

=== stdout ===
=== stderr ===
error[E0658]: `impl Trait` in type aliases is unstable
 --> /home/runner/work/glacier/glacier/ices/101940.rs:8:20
  |
8 |     type Fut<'a> = impl ::std::future::Future + 'a
  |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
  = help: add `#![feature(type_alias_impl_trait)]` to the crate attributes to enable

error: aborting due to previous error

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