RFR (S): Update statistics to capture update-refs, partial root scans

[Zhengyu Gu]

Good to me.

-Zhengyu

On 04/26/2017 02:29 PM, Aleksey Shipilev wrote:
> Hi,
>
> This change adds the details on rootset scanning for update-refs and partial. It
> also renames "Drain SATB" to "Finish Queues", which conveys the intent better.
>
> Fix:
>  http://cr.openjdk.java.net/~shade/shenandoah/stats-update-refs/webrev.01/
>
> Testing: hotspot_gc_shenandoah
>
> Thanks,
> -Aleksey
>