hg: shenandoah/jdk: [cherry pick] 8214362: C2: gc interface entry point for split if

[rwestrel at redhat.com]

Changeset: 7ae67e505b4e
Author:    roland
Date:      2018-11-28 09:49 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/7ae67e505b4e

[cherry pick] 8214362: C2: gc interface entry point for split if
Reviewed-by: rkennke, thartmann

! 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/shenandoah/c2/shenandoahSupport.cpp
! src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.hpp
! src/hotspot/share/opto/loopnode.hpp
! src/hotspot/share/opto/loopopts.cpp