ices/72278.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#72278

pub struct RefAny { }

impl RefAny {
    pub fn downcast_mut<'a, U: 'static>(&'a mut self) -> Option<&'a mut U> {
        unsafe { self.downcast_mut_unchecked::<'a, U>() } // <- panic here in lifetime resolution
    }

    unsafe fn downcast_mut_unchecked<'a, U>(&'a mut self) -> Option<&'a mut U> {
        None
    }
}

=== stdout ===
=== stderr ===
error[E0601]: `main` function not found in crate `72278`
  --> /home/runner/work/glacier/glacier/ices/72278.rs:1:1
   |
1  | / pub struct RefAny { }
2  | |
3  | | impl RefAny {
4  | |     pub fn downcast_mut<'a, U: 'static>(&'a mut self) -> Option<&'a mut U> {
...  |
10 | |     }
11 | | }
   | |_^ consider adding a `main` function to `/home/runner/work/glacier/glacier/ices/72278.rs`

warning: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present
 --> /home/runner/work/glacier/glacier/ices/72278.rs:5:48
  |
5 |         unsafe { self.downcast_mut_unchecked::<'a, U>() } // <- panic here in lifetime resolution
  |                                                ^^
...
8 |     unsafe fn downcast_mut_unchecked<'a, U>(&'a mut self) -> Option<&'a mut U> {
  |                                      -- the late bound lifetime parameter is introduced here
  |
  = note: `#[warn(late_bound_lifetime_arguments)]` on by default
  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
  = note: for more information, see issue #42868 <https://github.com/rust-lang/rust/issues/42868>

error: aborting due to previous error; 1 warning emitted

For more information about this error, try `rustc --explain E0601`.
==============