[Bug other/80678] g++.dg/cpp1y/constexpr-79681-2.C fails with ICE starting with r247678

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80678

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
It doesn't fail on x86_64/i686 where I've tested it.
Seems this is because r237426 has not been backported (and neither earlier
r237319).  Richard, do we want to backport those?  Aren't those wrong-code
fixes (besides also fixing this ICE)?