David Eichmann authored May 14, 2019 and Marge Bot committed May 25, 2019

Libffi is ultimately built from a single archive file (e.g.
libffi-tarballs/libffi-3.99999+git20171002+77e130c.tar.gz).
The file can be seen as the shallow dependency for the whole
libffi build. Hence, in all libffi rules, the archive is
`need`ed and the build directory is `trackAllow`ed.