ices/63695.rs: fixed with errors

=== stdout ===
=== stderr ===
warning: the feature `const_generics` is incomplete and may cause the compiler to crash
 --> /home/runner/work/glacier/glacier/ices/63695.rs:1:12
  |
1 | #![feature(const_generics)]
  |            ^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default

error: erroneous constant encountered
 --> /home/runner/work/glacier/glacier/ices/63695.rs:5:43
  |
5 |     fn test<const A: i32>(&self) -> i32 { A }
  |                                           ^

error: aborting due to previous error

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