ices/65394.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#65394

=== stdout ===
=== stderr ===
error[E0017]: references in constants may only refer to immutable values
 --> /home/runner/work/glacier/glacier/ices/65394.rs:3:13
  |
3 |     let r = &mut x;
  |             ^^^^^^ constants require immutable values

[ERROR rustc_mir::transform::qualify_consts] old validator: [(/home/runner/work/glacier/glacier/ices/65394.rs:3:13: 3:19, "MutBorrow(Mut { allow_two_phase_borrow: false })")]
[ERROR rustc_mir::transform::qualify_consts] new validator: [(/home/runner/work/glacier/glacier/ices/65394.rs:3:13: 3:19, "MutBorrow(Mut { allow_two_phase_borrow: false })"), (/home/runner/work/glacier/glacier/ices/65394.rs:2:9: 2:10, "LiveDrop")]
error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable
 --> /home/runner/work/glacier/glacier/ices/65394.rs:3:13
  |
2 |     let x = Vec::<i32>::new();
  |         - help: consider changing this to be mutable: `mut x`
3 |     let r = &mut x;
  |             ^^^^^^ cannot borrow as mutable

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0017, E0596.
For more information about an error, try `rustc --explain E0017`.
==============