RFR(XS): 8224573: Fix windows build after JDK-8221507

[Aleksey Shipilev]

On 5/22/19 8:59 AM, Thomas Stüfe wrote:
> 32bit should be enough for number of regions I think. If I am not mistaken,
> they have a min region size of 256K, so this covers a heap of ~1000 tb?

Yes, u4 should be enough. That would require some light metadata refactoring and testing, so I am
fine with doing that in a separate follow-up fix.

-Aleksey