[Bug c++/69681] C/C++ FEs do not consider comparisons of distinct function pointers to be constant expressions

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69681

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I don't think "(int)(&foo != &bar)" is a valid constant integer expression in
either C or C++. (definitely not in C).  This is why GCC rejects it.