Atomic intrinsics : use const generic ordering, part 2 This completes what got started in https://github.com/rust-lang/rust/pull/141507 by using a const generic for the ordering for all intrinsics. It is based on that PR; only the last commit is new. Blocked on: - https://github.com/rust-lang/rust/pull/141507 - https://github.com/rust-lang/rust/pull/141687 - https://github.com/rust-lang/stdarch/pull/1811 - https://github.com/rust-lang/rust/pull/141964 r? `@bjorn3`