RFR: Refactor region flags into FSM

[Aleksey Shipilev]

On 08/24/2017 03:39 PM, Zhengyu Gu wrote:
> Fail to commit an uncommitted region, does not necessarily mean out-of-memory, you may still have
> plenty regions in free set after this region, may make sense to have free set to skip this region
> and continue?

Yes, we shall do that when refactoring free set.

But as far as current code is concerned, we are at allocation path that should transit the region to
proper state. Failure to reach that state is fatal. Therefore I think crashing the VM is better
choice in this case...

Thanks,
-Aleksey