hg: shenandoah/jdk10/hotspot: Reinstate "Purge" block in final-mark stats

[ashipile at redhat.com]

Changeset: 4783a964a0f7
Author:    shade
Date:      2017-07-20 21:49 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk10/hotspot/rev/4783a964a0f7

Reinstate "Purge" block in final-mark stats

! src/share/vm/gc/shenandoah/shenandoahCollectorPolicy.hpp