hg: shenandoah/jdk10: Cherry-pick 8191887: assert(b->is_Bool()) in PhaseIdealLoop::clone_iff() due to Opaque4 node

[rwestrel at redhat.com]

Changeset: e3d076dce734
Author:    roland
Date:      2018-01-31 16:26 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk10/rev/e3d076dce734

Cherry-pick 8191887: assert(b->is_Bool()) in PhaseIdealLoop::clone_iff() due to Opaque4 node
Summary: add special handling for graph shape If->Opaque4->Bool->CmpP
Reviewed-by: kvn

! src/hotspot/share/opto/loopnode.hpp
! src/hotspot/share/opto/loopopts.cpp
+ test/hotspot/jtreg/compiler/unsafe/TestLoopUnswitching.java