XXX: Removing unused declarations (thus, unused headers can trigger
XXX: it) sometimes causes gcc to generate substantially different
XXX: code. Dunno why but it looks rather like a gcc bug.
This merges in all such remaining changes from the Linux port of the
NetBSD games, except in hunt (where substantial changes from OpenBSD
need to be looked at).
Some such changes were previously covered in PRs bin/6041, bin/6146,
bin/6148, bin/6150, bin/6151, bin/6580, bin/6660, bin/7993, bin/7994,
bin/8039, bin/8057 and bin/8093.