track renamed and removed library feature gates

Code

#![feature(stdsimd)]

fn main() {
    unsafe { core::arch::x86_64::_xbegin(); }
}

Current output

Compiling playground v0.0.1 (/playground)
error[E0658]: use of unstable library feature `stdarch_x86_rtm`
 --> src/main.rs:4:14
  |
4 |     unsafe { core::arch::x86_64::_xbegin(); }
  |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #111138 <https://github.com/rust-lang/rust/issues/111138> for more information
  = help: add `#![feature(stdarch_x86_rtm)]` to the crate attributes to enable
  = note: this compiler was built on 2025-05-25; consider upgrading it if it is out of date

error[E0635]: unknown feature `stdsimd`
 --> src/main.rs:1:12
  |
1 | #![feature(stdsimd)]
  |            ^^^^^^^

Some errors have detailed explanations: E0635, E0658.
For more information about an error, try `rustc --explain E0635`.
error: could not compile `playground` (bin "playground") due to 2 previous errors

Desired output

error[E0557]: feature has been removed
 --> src/main.rs:1:12
  |
1 | #![feature(stdsimd)]
  |            ^^^^^^^ feature has been removed
  |
  = note: removed in 1.78 (you are currently using 1.89-nightly)
  = note: this feature has been split into many smaller features; see <https://github.com/rust-lang/rust/issues/27731#issuecomment-1937538034> for an exhaustive list

Rationale and extra context

we have something like this for lang features, whose removal we explicitly track:

error[E0557]: feature has been removed
 --> src/main.rs:3:12
  |
3 | #![feature(external_doc)]
  |            ^^^^^^^^^^^^ feature has been removed
  |
  = note: use #[doc = include_str!("filename")] instead, which handles macro invocations

but there is no way to track this for libs features, which leads to unnecessarily confusing errors. it would be nice if we could help people out more here, especially since the people seeing this error are likely not the crate authors but just people who happen to be using a nightly toolchain.

Other cases

Rust Version

1.89.0-nightly

(2025-05-25 283db70ace62a0ae704a)

Anything else?

No response