[Bug libstdc++/91263] unordered_map and unordered_set operator== double key comparison causes exponential behavior

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91263

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Fixed on trunk. Let's keep this open and decide whether to backport it to the
release branches.