[Bug c++/124412] different and confusing diagnostic order for = 0 / = 0u inside class vs at namespace scope

[attackerj1113 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124412

--- Comment #1 from Jian Ma <attackerj1113 at gmail dot com> ---
https://godbolt.org/z/hjez3jxrY