ices/55414.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#55414

macro_rules! bug {
    ($expr:expr) => {
        #[rustc_dummy = $expr] // Any key-value attribute, not necessarily `doc`
        struct S;
    };
}

// Any expressions containing macro call `X` that's more complex than `X` itself.
// Parentheses will work.
bug!((line!()));

fn main() {}

=== stdout ===
=== stderr ===
error: unexpected token: `(10u32)`
  --> /home/runner/work/glacier/glacier/ices/55414.rs:3:25
   |
3  |         #[rustc_dummy = $expr] // Any key-value attribute, not necessarily `doc`
   |                         ^^^^^
...
10 | bug!((line!()));
   | ---------------- in this macro invocation
   |
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0658]: the `#[rustc_dummy]` attribute is just used for rustc unit tests and will never be stable
  --> /home/runner/work/glacier/glacier/ices/55414.rs:3:9
   |
3  |         #[rustc_dummy = $expr] // Any key-value attribute, not necessarily `doc`
   |         ^^^^^^^^^^^^^^^^^^^^^^
...
10 | bug!((line!()));
   | ---------------- in this macro invocation
   |
   = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0658`.
==============