ices/78450.rs: fixed with no errors (#831)

=== stdout ===
=== stderr ===
warning: the feature `type_alias_impl_trait` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /home/runner/work/glacier/glacier/ices/78450.rs:2:12
  |
2 | #![feature(type_alias_impl_trait)]
  |            ^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default
  = note: see issue #63063 <rust-lang/rust#63063> for more information

warning: 1 warning emitted

==============

Co-authored-by: rustbot <[email protected]>

Author: github-actions[bot]