These methods were stabilized for the integer atomics in #71843, but the methods
were not added for the non-integer atomics `AtomicBool` and `AtomicPtr`.
Revert adding Atomic::from_mut.
This reverts #74532, which made too many assumptions about platforms, breaking some things.
Will need to be added later with a better way of gating on proper alignment, without hardcoding cfg(target_arch)s.
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To be merged if fixing from_mut (#76965) takes too long.
r? @ghost
This made too many assumptions about platforms, breaking some things.
Will need to be added later with a better way of gating on proper
alignment, without hardcoding cfg(target_arch)s.
