32-bit compat test suite

From: Alan Somers <asomers_at_freebsd.org>
Date: Sun, 05 Dec 2021 14:55:12 UTC
Would it be possible to start running the FreeBSD test suite for i386
in a jail on amd64 in CI?  The 32-bit compat layer is a big area that
gets very little test coverage from the regular test suite.

I haven't tried doing this on the bench lately.  I suspect there would
be some tests that can't work this way.