The test is currently disabled due to JDK-8325632. The issue is very intermittent but reproduces after a large number of iterations:

-DPreferCommandLineFlags=true -XX:+AlwaysIncrementalInline -XX:+MonomorphicArrayCheck -XX:+UncommonNullCast -XX:MaxNodeLimit=90000
test/hotspot/jtreg/compiler/valhalla/inlinetypes/TestNullableArrays.java#id4

# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/workspace/open/src/hotspot/share/opto/node.hpp:1011), pid=3286918, tid=3286938
# assert(is_Multi()) failed: invalid node class: Con

Current CompileTask:
C2:8652 1190 b 4 compiler.valhalla.inlinetypes.TestNullableArrays::test107 (80 bytes)

Stack: [0x00007fc650aec000,0x00007fc650bec000], sp=0x00007fc650be6b00, free space=1002k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x17a8ee1] MemNode::optimize_simple_memory_chain(Node*, TypeOopPtr const*, Node*, PhaseGVN*)+0xa11 (node.hpp:1011)
V [libjvm.so+0x17a948e] MemNode::optimize_memory_chain(Node*, TypePtr const*, Node*, PhaseGVN*)+0x2e
V [libjvm.so+0x17b50df] LoadNode::Ideal(PhaseGVN*, bool)+0x1ff
V [libjvm.so+0x17b5cd2] LoadNNode::Ideal(PhaseGVN*, bool)+0x1c2
V [libjvm.so+0x199743e] PhaseIterGVN::transform_old(Node*)+0xce
V [libjvm.so+0x199c365] PhaseIterGVN::optimize()+0xc5
V [libjvm.so+0xc13b30] Compile::inline_incrementally_cleanup(PhaseIterGVN&)+0x360
V [libjvm.so+0xc148fe] Compile::inline_incrementally(PhaseIterGVN&)+0x42e
V [libjvm.so+0xc1741e] Compile::Optimize()+0x47e
V [libjvm.so+0xc1acfd] Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x1d8d
V [libjvm.so+0xa09025] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x4b5
V [libjvm.so+0xc2a640] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x780
V [libjvm.so+0xc2bea0] CompileBroker::compiler_thread_loop()+0x530
V [libjvm.so+0x11f0bcb] JavaThread::thread_main_inner()+0x13b
V [libjvm.so+0x1ce34c6] Thread::call_run()+0xb6
V [libjvm.so+0x18f7738] thread_native_entry(Thread*)+0x118