See PHI336. See https://discourse.phabricator-community.org/t/using-the-filefinder-class-withsuffix-and-withname-return-entries-with-either-the-suffix-or-the-name-match/1035?u=dangerouslyil.
Currently, withName() and withSuffix() mean "with either the name or the suffix", which isn't how any other Query class works.
Note that "name" means "exact name", per find semantics, so this combination isn't necesarily terribly useful. However, the current behavior is clearly surprising given that everything else in the project works differently.