Example failure states for CGB mode

[tobiasvl]

It'd be nice if a couple of common failure states for running this test in a CGB emulator were covered. This test is still very useful for extending a DMG emulator with CGB functionality when cgb-acid2 still is a long ways from passing.

[mattcurrie]

Yes, that's a good idea :) I'll add some failure states for when running on a CGB emulator when I get some time to work on the v1.1 release.