[Bug libstdc++/102916] cmath constexpr can lead to ODR violations/incorrect results

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102916

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
And we already have a bug report about the presence of constexpr being
non-conforming. IIRC the conclusion has been "yes, but it's more useful to
support this than to strictly conform".