[Bug c++/114067] GCC gives wrong diagnostic in the definition of a static data member of same class type

[jlame646 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114067

--- Comment #1 from Jason Liam <jlame646 at gmail dot com> ---
That is, even if the type of `a` was complete the program would've been
ill-formed. So saying only that `A` is incomplete is the problem doesn't seem
right.