[Bug libgcc/84292] __sync_add_and_fetch returns the old value instead of the new value

[andreast at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84292

--- Comment #7 from Andreas Tobler <andreast at gcc dot gnu.org> ---
I can do a backport w/o an open PR' right? If so, then the PR can be set to
resolved.