Add missing CFLAGS and LDADD to unit tests [v9.18]
A number of unit tests needed to be told where to find their libraries and matching headers.
(cherry picked from commit 24d420f2)
Backport of !6369 (merged)
A number of unit tests needed to be told where to find their libraries and matching headers.
(cherry picked from commit 24d420f2)
Backport of !6369 (merged)