...only when running under minimal/do, of course.
The tests in question mostly fail because they're testing particular
dependency-related behaviour, and minimal/do doesn't support dependencies,
so naturally it doesn't work.
It actually decreases readability of the .do files - by not making it
explicit when you're going into a subdir.
Plus it adds ambiguity: what if there's a dirname.do *and* a dirname/all?
We could resolve the ambiguity if we wanted, but that adds more code, while
taking out this special case makes *less* code and improves readability.
I think it's the right way to go.
