ices/76510.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#76510

struct Dummy;

impl Dummy {
    const fn func(&mut self) -> usize {
        42
    }
}

const _: &[usize] = &[0; {
    const DUMMY: &Dummy = &Dummy;
    DUMMY.func()
}];

=== stdout ===
=== stderr ===
error[E0601]: `main` function not found in crate `76510`
  --> /home/runner/work/glacier/glacier/ices/76510.rs:1:1
   |
1  | / struct Dummy;
2  | |
3  | | impl Dummy {
4  | |     const fn func(&mut self) -> usize {
...  |
11 | |     DUMMY.func()
12 | | }];
   | |___^ consider adding a `main` function to `/home/runner/work/glacier/glacier/ices/76510.rs`

error[E0596]: cannot borrow data in a `&` reference as mutable
  --> /home/runner/work/glacier/glacier/ices/76510.rs:11:5
   |
11 |     DUMMY.func()
   |     ^^^^^ cannot borrow as mutable

error[E0658]: mutable references are not allowed in constant functions
 --> /home/runner/work/glacier/glacier/ices/76510.rs:4:19
  |
4 |     const fn func(&mut self) -> usize {
  |                   ^^^^^^^^^
  |
  = note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
  = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0596, E0601, E0658.
For more information about an error, try `rustc --explain E0596`.
==============