hg: shenandoah/jdk8u/hotspot: Use previous mark bitmap when iterating marked objects, not current, which might not be completed yet.

[roman at kennke.org]

Changeset: 1407e1b07b44
Author:    rkennke
Date:      2016-07-21 00:00 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk8u/hotspot/rev/1407e1b07b44

Use previous mark bitmap when iterating marked objects, not current, which might not be completed yet.

! src/share/vm/gc_implementation/shenandoah/shenandoahHeap.cpp