[Bug libstdc++/119163] std::equal cannot be used with debug mode iterators in constant expressions

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119163

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Fixed by r16-5845-g8a2e6590cc4a2f but that can't be backported to gcc-15.