[Bug target/126293] Add x86-64 option to turn on 128-bit inline atomic loads/stores

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126293

--- Comment #11 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Florian Weimer from comment #9)
> Thanks. Can we turn this on automatically when targeting named CPUs
> (-march=diamondrapids)? And the changes should be compatible with the
> eventual fix for bug 94649.

Done.