ices/84768.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#84768

#![feature(fn_traits)]

fn transform_mut<F>(f: F) where F: for<'b> FnOnce(&'b mut u8) {
    <F as FnOnce(&mut u8)>::call_once(f, 1)
}

=== stdout ===
=== stderr ===
error[E0601]: `main` function not found in crate `84768`
 --> /home/runner/work/glacier/glacier/ices/84768.rs:1:1
  |
1 | / #![feature(fn_traits)]
2 | |
3 | | fn transform_mut<F>(f: F) where F: for<'b> FnOnce(&'b mut u8) {
4 | |     <F as FnOnce(&mut u8)>::call_once(f, 1)
5 | | }
  | |_^ consider adding a `main` function to `/home/runner/work/glacier/glacier/ices/84768.rs`

error[E0229]: associated type bindings are not allowed here
 --> /home/runner/work/glacier/glacier/ices/84768.rs:4:11
  |
4 |     <F as FnOnce(&mut u8)>::call_once(f, 1)
  |           ^^^^^^^^^^^^^^^ associated type not allowed here

error[E0308]: mismatched types
 --> /home/runner/work/glacier/glacier/ices/84768.rs:4:42
  |
4 |     <F as FnOnce(&mut u8)>::call_once(f, 1)
  |                                          ^ expected tuple, found integer
  |
  = note: expected tuple `(&mut u8,)`
              found type `{integer}`

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0229, E0308, E0601.
For more information about an error, try `rustc --explain E0229`.
==============