It turns out this wasn't in 4.4BSD. I had a false positive for gdc.c
(which is in 4.4BSD, but part of gated, not this). gdc.c comes from the
ncurses tests, so it shouldn't have this copyright. This version is
mostly Amos Shapir and John Lupien's code. It comes from ncurses test
directory. ncurses has made dozens of improvements to this file since
we imported it in 1997 (which pre-dates their online history), so it's
not clear if their new copyright applies (which doesn't mention Amos
or John) or if some other copyright applies. In any case, it wasn't
4.4BSD, so revert this.
This reverts commit 6ed7d0e3ac.
Sponsored by: Netflix
In most cases, usage does not return, so mark them as __dead2. For the
cases where they do return, they have not been marked __dead2.
Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/735