[Bug libstdc++/114865] [13/14/15 Regression] std::atomic::compare_exchange_strong seems to hang under GCC 13 for C++11

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114865

--- Comment #14 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Because a constexpr function can't have an if statement in C++11.

But maybe we should just clear padding unconditionally for C++11.