hg: shenandoah/jdk9/hotspot: implicit null check in read barrier when compressed oops are enabled

[rwestrel at redhat.com]

Changeset: b022598e2a2b
Author:    roland
Date:      2016-09-09 14:59 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk9/hotspot/rev/b022598e2a2b

implicit null check in read barrier when compressed oops are enabled

! src/cpu/x86/vm/x86_64.ad