hg: shenandoah/jdk10: Cherry-pick 8186027: C2: loop strip mining

[rwestrel at redhat.com]

Changeset: 16f17f40cecf
Author:    roland
Date:      2018-02-08 13:24 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk10/rev/16f17f40cecf

Cherry-pick 8186027: C2: loop strip mining
Reviewed-by: kvn, neliasso

! src/hotspot/share/opto/c2_globals.hpp
! src/hotspot/share/opto/cfgnode.cpp
! src/hotspot/share/opto/classes.hpp
! src/hotspot/share/opto/compile.cpp
! src/hotspot/share/opto/ifnode.cpp
! src/hotspot/share/opto/loopPredicate.cpp
! src/hotspot/share/opto/loopTransform.cpp
! src/hotspot/share/opto/loopnode.cpp
! src/hotspot/share/opto/loopnode.hpp
! src/hotspot/share/opto/loopopts.cpp
! src/hotspot/share/opto/macro.cpp
! src/hotspot/share/opto/node.hpp
! src/hotspot/share/opto/opaquenode.cpp
! src/hotspot/share/opto/opaquenode.hpp
! src/hotspot/share/opto/shenandoahSupport.cpp
! src/hotspot/share/runtime/arguments.cpp
! test/hotspot/jtreg/compiler/loopopts/UseCountedLoopSafepointsTest.java