Auto merge of #86233 - JohnTitor:stabilize-simd-x86-bittest, r=Amanieu
Auto merge of #86233 - JohnTitor:stabilize-simd-x86-bittest, r=Amanieu

Stabilize `simd_x86_bittest` feature

This pulls https://github.com/rust-lang/stdarch/pull/1180, FCP is complete: https://github.com/rust-lang/rust/issues/59414#issuecomment-826072554
Closes #59414

aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust