[Bug libstdc++/68190] iterator mix up with set::find and heterogenous lookup

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68190

--- Comment #5 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
710         { return _M_t._M_find_tr(__x); }