Ever since I was a young lad, you could declare the same variables in
multiple places as long as they were all unintialized. But long about
FreeBSD 13, Clang stopped allowing this behavior. It also stopped being
the default behavior in GCC 10.

I have been dragging this fix around for more than a year, unsure whether
it was going to break older builds. But since it has started affecting
the Almighty Linux build, it is time to commit (literally and figuratively).