ices/113021.rs: fixed with errors

=== stdout ===
=== stderr ===
error[E0425]: cannot find value `N_ISLANDS` in this scope
 --> /home/runner/work/glacier/glacier/ices/113021.rs:3:40
  |
3 | pub async fn something(path: &[[usize; N_ISLANDS]; PrivateStruct]) -> usize {
  |                                        ^^^^^^^^^ not found in this scope

error[E0425]: cannot find value `PrivateStruct` in this scope
 --> /home/runner/work/glacier/glacier/ices/113021.rs:3:52
  |
3 | pub async fn something(path: &[[usize; N_ISLANDS]; PrivateStruct]) -> usize {
  |                                                    ^^^^^^^^^^^^^ not found in this scope

warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /home/runner/work/glacier/glacier/ices/113021.rs:1:12
  |
1 | #![feature(generic_const_exprs)]
  |            ^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #76560 <rust-lang/rust#76560> for more information
  = note: `#[warn(incomplete_features)]` on by default

error[E0730]: cannot pattern-match on an array without a fixed length
 --> /home/runner/work/glacier/glacier/ices/113021.rs:5:9
  |
5 |         [] | _ => 0,
  |         ^^

error: aborting due to 3 previous errors; 1 warning emitted

Some errors have detailed explanations: E0425, E0730.
For more information about an error, try `rustc --explain E0425`.
==============