Hadrian: Add Missing Libffi Dependencies #16653

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 needed and the build directory is trackAllowed.