Rename misleading features

[calebzulawski]

Renamed features according to rust-lang/rust#100752 (and #1325)

This works on master, but rust-lang/rust#103750 hasn't hit nightly yet. landed on nightly

An open question: in is_x86_feature_detected, should avx512gfni be an alias for gfni (even though it doesn't actually check for avx512f), or should it be a separate feature that checks the multiple feature flags required to enable the AVX-512 GFNI instructions? (and the same goes for avx512vaes and avx512vpclmulqdq)

[rust-highfive]

r? @Amanieu

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[Amanieu]

I think avx512gfni can just be an alias for gfni, however it would be nice to have a deprecation warning trigger when you use it.

[calebzulawski]

I added a deprecation warning, but the way it's emitted is admittedly a hack. It emits this reasonable message:

warning: use of deprecated macro `deprecated_feature`: the `avx512gfni` feature has been renamed to `gfni`
  --> crates/std_detect/tests/x86-specific.rs:40:33
   |
40 |     println!("avx512gfni {:?}", is_x86_feature_detected!("avx512gfni"));
   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(deprecated)]` on by default
   = note: this warning originates in the macro `is_x86_feature_detected` (in Nightly builds, run with -Z macro-backtrace for more info)