As noted by brooks/emaste, this is the wrong approach to take.
Revert the changes so brooks can apply a more proper change.
Requested by: brooks, emaste
Having kyua in the base system will simplify automated testing in CI and
eliminates bootstrapping issues on new platforms.
The build of kyua is controlled by WITH(OUT)_TESTS_SUPPORT.
Reviewed by: emaste
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24103