[Bug libstdc++/67403] std::regex is not matching

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67403

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Iirc regex was not implemented in 4.8.x. Try 4.9 and above.