Atomic Coherence with Indirection Copies is Broken

[lightsighter]

Collective indirection copies that rely on atomic coherence on any of their region requirements will not work correctly right now. I've placed a guard in the runtime to detect if we're going to hit the bad path so we can fix it when it occurs, but creating this issue for now to remind myself that this problem is outstanding.

[apryakhin]

@lightsighter Is this a legion-specific issue?

[lightsighter]

Yes, this is a Legion-specific issue.