WIP: zink: do not do out-of-renderpass clears
Sadly, the out-of-renderpass clears have issues, where they don't get correctly resolved in all cases.
So let's disable them for now. I'm sure this will make Mike upset, so he'll fix the issue! I'm not smart enough!
This is on top of !10950 (closed) because otherwise we get additional failures in the test. There's also a few other patches thrown in, but I don't think they make any difference. They were just things I discovered while hacking.
I would really prefer not merging this, but I can't for the life of me figure out how to fix this. @zmike?