t/op/time.t See if time functions work
t/op/time_loop.t Test that very large values don't hang gmtime and localtime.
t/op/tr.t See if tr works
+t/op/tr_latin1.t See if tr works, but file isn't encoded in UTF-8
t/op/undef.t See if undef works
t/op/universal.t See if UNIVERSAL class works
t/op/unlink.t See if unlink works