hg: shenandoah/jdk: Full GC should not trash empty regions

[ashipile at redhat.com]

Changeset: eef8fad72696
Author:    shade
Date:      2018-03-20 16:25 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/eef8fad72696

Full GC should not trash empty regions

! src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.cpp
! src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.hpp
! src/hotspot/share/gc/shenandoah/shenandoahMarkCompact.cpp