Time to upgrade buildfarm coverage for some EOL'd OSes?

Hi,

I noticed that for NetBSD we only have one animal, and it's running
EOL'd release 7. To give decent visibility of relevant portability
problems it'd be nice to have one of the current supported releases[1]
in there. CC'ing owner; any interest in updating this animal to 9.x?

For FreeBSD the situation is better, we have HEAD (bleeding edge 14),
13.x, and then loach running 10.3 which is dead. Given that 12.x and
13.x are supported[2] (well, 11.4 is just about done), perhaps it'd
make sense to cover 12.x rather than 10.x?

I don't know too much about DragonflyBSD, but I happened to be
surveying operating systems we support (by the "it's in the build farm
so we're going to keep it green" definition) in the context of some
AIO work, and I learned that they'd ripped the native AIO support out
of this one at some point, which caused me to focus on the versions.
Animal conchuela is running 4.4 (2016) while 6.0 is current[3].
Again, if we're going to have one example of a rare OS that someone
cares about, I think it'd be useful to have a current one?

For OpenBSD we have the current[4] and previous major releases
covered, so that's cool, and then there's a 5.9 system, which is long
dead and could probably be put to better use, but at least we don't
lack coverage there.

In all these cases there are more options that could be turned on, in
case someone is interested in extending what's tested. From my notes:

FreeBSD 12:

pkg install -y gmake ccache git flex bison readline p5-IPC-Run llvm
pkgconf python3 libxslt openldap-client gettext tcl86 krb5

--enable-cassert --enable-debug --enable-tap-tests --enable-nls
--with-gssapi --with-icu --with-tcl --with-perl --with-python
--with-pam --with-ldap --with-libxml --with-libxslt --with-lz4
--with-openssl --with-llvm --with-libs=/usr/local/lib
--with-includes=/usr/local/include CC="ccache cc" CXX="ccache c++"
CLANG="ccache clang90" LLVM_CONFIG="llvm-config90"

NetBSD 9:

pkgin -y install gmake git flex bison ccache readline
mozilla-rootcerts p5-IPC-Run llvm clang pkg-config icu lz4 libxslt tcl

--enable-cassert --enable-debug --enable-tap-tests --enable-nls
--with-gssapi --with-icu --with-tcl --with-perl --with-python
--with-pam --with-ldap --with-libxml --with-libxslt --with-lz4
--with-openssl --with-llvm --with-includes=/usr/pkg/include CC="ccache
cc" CXX="ccache c++" CLANG="ccache clang" LLVM_CONFIG="llvm-config"
PYTHON="python3.8" LDFLAGS="-R/usr/pkg/lib"

OpenBSD 6.9:

pkg_add -z ccache gmake git bison autoconf-2.69 readline screen--
p5-IPC-Run icu4c python3 libxml libxslt openldap-client--gssapi
tcl-8.6.8 gettext-tools

--enable-cassert --enable-debug --enable-tap-tests --enable-nls
--with-icu --with-tcl --with-perl --with-python --with-bsd-auth
--with-ldap --with-libxml --with-libxslt --with-lz4 --with-openssl
CC="ccache cc"

(I have never succeeded in getting our LLVM stuff running on OpenBSD;
there's something wrong with their LLVM package the way we use it and
their retpoline mitigation stuff, not investigated further.)

(Hmm, in hindsight, I don't know why we need "--with-bsd-auth" instead
of detecting it, but I don't plan to work on that...)

[1] https://www.netbsd.org/releases/
[2] https://www.freebsd.org/releases/
[3] https://www.dragonflybsd.org/
[4] https://www.openbsd.org/