hg: shenandoah/jdk8u/hotspot: [backport] Fix up pointer volatility

[ashipile at redhat.com]

Changeset: 642fc8cfdc03
Author:    shade
Date:      2017-05-12 13:42 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk8u/hotspot/rev/642fc8cfdc03

[backport] Fix up pointer volatility

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