In principle we could script this so that each max-version.c is compiled
26 times, once per possible MAX_VERSION, but I haven't implemented
that here: just pinning to the oldest possible version is sufficient to
reproduce #2796.
These aren't included in the installed-tests, since they don't really
do anything at runtime (the important thing is that they compile
without warnings).
Reproduces: #2796
Signed-off-by: Simon McVittie <smcv@collabora.com>