[Bug target/96189] Failure to use eflags from cmpxchg on x86

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96189

--- Comment #1 from Gabriel Ravier <gabravier at gmail dot com> ---
PS : The extraneous movzx is already reported at
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96176