[Bug libstdc++/88996] Implement P0439R0 - Make std::memory_order a scoped enumeration.

[emsr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88996

--- Comment #6 from emsr at gcc dot gnu.org ---
Created attachment 45502
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45502&action=edit
New patch, C++20 only, several fixes, no memory_order ops.

Retesting.