[Bug c++/110158] Cannot use union with std::string inside in constant expression

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110158

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Odd, I thought I'd checked it when testing r14-4334-g28adad7a32ed92.

Seems like the same issue as PR 112642 though (which has a minimized version
without std::string).