Use uname -s to work out what Operating System we're on.
FreeBSD have a dependency to use emacs to byte-compile a LISP file.
Don't use this dependency on NetBSD - avoids downloading emacs just
to compile one file.
Use uname -s to work out the Operating System.
FreeBSD has install-info and /usr/share/info/dir by default.
NetBSD doesn't, so, for now, don't try to do this on NetBSD.