Detect usage of invalid atomic ordering in memory fences
Detect usage of `core::sync::atomic::{fence, compiler_fence}` with `Ordering::Relaxed` and suggest valid alternatives.
changelog: Extend `invalid_atomic_ordering` to lint memory fences
Fixes#5026
Detect usage of invalid atomic ordering modes such as
`Ordering::{Release, AcqRel}` in atomic loads and
`Ordering::{Acquire, AcqRel}` in atomic stores.
