running gc/shenandoah/compiler/BarrierInInfiniteLoop.java with -XX:ShenandoahGCMode=iu causes the following failure:

# Internal Error (/home/roland/jdk-jdk/src/hotspot/share/opto/loopnode.cpp:3765), pid=562476, tid=562488
# assert(_ltree_root->_child == __null || C->has_loops() || only_has_infinite_loops() || C->has_exception_backedge()) failed: parsing found no loops but there are some