SIMD removal from rust

[driemworks]

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Description of bug

SIMD was removed from the latest rust nightly version rust-lang/rust#117372 which causes ahash 0.7.7 to break: tkaitchuck/aHash#200. This has been resolved in versions >= 0.8.X tkaitchuck/aHash#183.

• run cargo +nightly tree -i ahash@0.7.7 to see the full dependency graph.
• more info: https://users.rust-lang.org/t/error-e0635-unknown-feature-stdsimd/106445

error[E0635]: unknown feature `stdsimd`
  --> /home/XXXX/.cargo/registry/src/index.crates.io-6f17d22bba15001f/ahash-0.7.7/src/lib.rs:33:42
   |
33 | #![cfg_attr(feature = "stdsimd", feature(stdsimd))]
   |                                          ^^^^^^^

For more information about this error, try `rustc --explain E0635`.
error: could not compile `ahash` (lib) due to 1 previous error
warning: build failed, waiting for other jobs to finish...

Steps to reproduce

1. Clone the polkadot-sdk master branch
2. Update to the latest rust nightly version (as of this comment: nightly-x86_64-unknown-linux-gnu - rustc 1.78.0-nightly (8ace7ea1f 2024-02-07))
3. Build the project

git clone https://github.com/paritytech/polkadot-sdk.git
rustup update nightly
cargo +nightly build --release

[ggwpez]

Hm, we can update criterion which seems to pull it in a lot and maybe some other deps.
Note that we normally use stable and not nightly to build, but its indeed a bummer.

PS: Updating criterion errors with this: rust-bitcoin/rust-bip39#64

[ggwpez]

Other ideas @bkchr ?

[burdges]

rust-lang/rust#27731 (comment)

rust-lang/stdarch#1486

rust-lang/rust#120930