RFR(XXS) 8222188: Shenandoah: Adjust Shenandoah work gang types

[Aleksey Shipilev]

On 4/9/19 4:59 PM, Zhengyu Gu wrote:
> Updated: http://cr.openjdk.java.net/~zgu/JDK-8222188/webrev.01/
OK. I think it still makes sense to add parameter comments to _safepoint_workers, just not change
the actual passed values?

-Aleksey