quite a few tests in F<t/> have not been refactored to use it. Refactoring
any of these tests, one at a time, is a useful thing TODO.
+The subdirectories F<base>, F<cmd> and F<comp>, that contain the most
+basic tests, should be excluded from this task.
+
=head2 Test that regen.pl was run
There are various generated files shipped with the perl distribution, for