It was causing intermittent failures on GTK. We'll no doubt want tools in the QA framework at some point, but probably not necessary for 6.0....
Also tries to fix a compile issue on gcc.
One test has pads of a bunch of different shapes and provokes some errors to make sure they're caught. The others are all past issues with the zone filler to make sure we don't suffer any regressions. (They should all just pass with no DRC errors.)