RFR: Print more details for weak ref and class unloading stats

[Roman Kennke]

Am 29.05.2017 um 20:12 schrieb Aleksey Shipilev:
> I would like to have more insight into "Weak References" and "Class Unloading"
> phases:
>  http://cr.openjdk.java.net/~shade/shenandoah/stats-purge-weakrefs/webrev.01/
>
> Sample report:
>  http://cr.openjdk.java.net/~shade/shenandoah/stats-purge-weakrefs/gcstats.txt
>
> Testing: hotspot_gc_shenandoah
>
> -Aleksey
>
>
Looks useful! Yes!