RFR: Verify humongous regions liveness

[Zhengyu Gu]

Looks good.

-Zhengyu

On 08/28/2017 01:55 PM, Aleksey Shipilev wrote:
> http://cr.openjdk.java.net/~shade/shenandoah/verifier-humongous-live/webrev.01/
> 
> We have skipped it before for simplicity, but we should really assert that live data accounted in
> humongous regions is also correct. Fixes the bug in marked humongous objects iteration too!
> 
> Testing: hotspot_gc_shenandoah
> 
> Thanks,
> -Aleksey
>