hg: shenandoah/jdk: Cherry-pick: 8213746: GC/C2 abstraction for C2 matcher

[roman at kennke.org]

Changeset: f8eae592a9bf
Author:    rkennke
Date:      2018-11-20 22:37 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/f8eae592a9bf

Cherry-pick: 8213746: GC/C2 abstraction for C2 matcher

! 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/gc/z/c2/zBarrierSetC2.cpp
! src/hotspot/share/gc/z/c2/zBarrierSetC2.hpp
! src/hotspot/share/opto/matcher.cpp
! src/hotspot/share/opto/matcher.hpp