RFR: Stats should not record past-shutdown events

[Roman Kennke]

Am 07.06.2017 um 18:38 schrieb Aleksey Shipilev:
> The decision to exit VM may come abruptly during concurrent phase. In this case,
> it makes little sense to record the performance data, because we will most
> likely record the degenerated cycle.
>
> Fix:
>   http://cr.openjdk.java.net/~shade/shenandoah/stats-skip-shutdown/webrev.01/
>
> Testing: hotspot_gc_shenandoah
>
> Thanks,
> -Aleksey
>
>
Yeah ok.

Roman