[Bug libstdc++/54005] Use __atomic_always_lock_free in libstdc++ is_lock_free instead of __atomic_is_lock_free

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54005

--- Comment #24 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Hans-Peter Nilsson from comment #22)
> Or do I misread that?  Are __alignof(x) and the result of alignas(x)
> in the declaration guaranteed to always be the same here?

Yes.