C2: assert(!in->is_CFG()) failed: CFG Node with no controlling input after JDK-8252372

Attached fuzzer test fails after

$ ../build/linux-x86_64-server-fastdebug/images/jdk/bin/java -XX:+UnlockDiagnosticVMOptions -Xcomp -XX:CompileOnly=Test -XX:-TieredCompilation Test

# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/home/shade/trunks/jdk/src/hotspot/share/opto/loopnode.cpp:4791), pid=3211328, tid=3211341
# assert(!in->is_CFG()) failed: CFG Node with no controlling input?

Current thread (0x00007f600c352a30): JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=3211341, stack(0x00007f5fa8238000,0x00007f5fa8339000)]


Current CompileTask:
C2: 244 7 !b Test::fMeth (249 bytes)

Stack: [0x00007f5fa8238000,0x00007f5fa8339000], sp=0x00007f5fa8333390, free space=1004k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x12d7df4] PhaseIdealLoop::build_loop_early(VectorSet&, Node_List&, Node_Stack&)+0x624
V [libjvm.so+0x12e2d3a] PhaseIdealLoop::build_and_optimize(LoopOptsMode)+0x49a
V [libjvm.so+0xa35515] PhaseIdealLoop::optimize(PhaseIterGVN&, LoopOptsMode)+0x2d5
V [libjvm.so+0xa3293f] Compile::Optimize()+0xd8f
V [libjvm.so+0xa340dd] Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x120d
V [libjvm.so+0x86983e] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x1ee
V [libjvm.so+0xa458e9] CompileBroker::invoke_compiler_on_method(CompileTask*)+0xf19
V [libjvm.so+0xa465c8] CompileBroker::compiler_thread_loop()+0x5a8
V [libjvm.so+0x19d6a51] JavaThread::thread_main_inner()+0x281
V [libjvm.so+0x19de184] Thread::call_run()+0x104
V [libjvm.so+0x155622e] thread_native_entry(Thread*)+0x10e


Bisection points to reliable failure after JDK-