RFR (S) 8243494: Shenandoah: set counters once per cycle

[Zhengyu Gu]

Looks good.

-Zhengyu

On 4/23/20 1:19 PM, Aleksey Shipilev wrote:
> RFE:
>    https://bugs.openjdk.java.net/browse/JDK-8243494
> 
> There are several places where we reuse the counters for different purposes, for example
> full_gc_roots. There are places where we accidentally count things twice, for example conc_mark. It
> would be hard-checked by JDK-8239786, so we need to fix it before then.
> 
> Fix:
>    https://cr.openjdk.java.net/~shade/8243494/webrev.01/
> 
> Testing: hotspot_gc_shenandoah, eyeballing logs
>