hg: shenandoah/jdk9/hotspot: CAS/CAE cause segfault when expected or value loaded is null

[rwestrel at redhat.com]

Changeset: 191da0ccfb8d
Author:    roland
Date:      2016-06-14 15:57 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk9/hotspot/rev/191da0ccfb8d

CAS/CAE cause segfault when expected or value loaded is null

! src/cpu/aarch64/vm/aarch64.ad
! src/cpu/aarch64/vm/macroAssembler_aarch64.cpp
! src/cpu/x86/vm/x86_64.ad