hg: shenandoah/jdk: Cherry-pick JDK-8213381: Hook to allow GC to inject Node::Ideal() calls plus Shenandoah parts

[roman at kennke.org]

Changeset: 7d01ab2fc30d
Author:    rkennke
Date:      2018-11-06 14:26 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/7d01ab2fc30d

Cherry-pick JDK-8213381: Hook to allow GC to inject Node::Ideal() calls plus Shenandoah parts

! src/hotspot/share/gc/shared/c2/barrierSetC2.hpp
! src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp
! src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.hpp
! src/hotspot/share/opto/callnode.cpp
! src/hotspot/share/opto/callnode.hpp
! src/hotspot/share/opto/loopnode.cpp
! src/hotspot/share/opto/loopopts.cpp
! src/hotspot/share/opto/memnode.cpp
! src/hotspot/share/opto/phaseX.cpp
! src/hotspot/share/opto/phaseX.hpp
! src/hotspot/share/opto/subnode.cpp