[Bug c++/87594] constexpr rejects-valid code with range-based for-loop

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87594

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Actually I guess we don't have to care about fn4/fn5 very much.