[Bug libstdc++/86164] std::regex crashes when matching long lines

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86164

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I started working on a patch to replace the recursion with iteration, but
didn't get it working yet.