The attached fuzzer test fails with the following assertion:

To reproduce:
$ java -Xbatch -Xmx1G Test.java 

#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/home/christian/jdk/open/src/hotspot/share/opto/loopTransform.cpp:692), pid=6413, tid=6425
# assert(cl->trip_count() > 0) failed: peeling a fully unrolled loop
#
# JRE version: Java(TM) SE Runtime Environment (16.0) (slowdebug build 16-internal+0-2020-10-16-0945385.christian...)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (slowdebug 16-internal+0-2020-10-16-0945385.christian..., mixed mode, tiered, compressed oops, g1 gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0xde6d8f] PhaseIdealLoop::do_peeling(IdealLoopTree*, Node_List&)+0xe5
..........
Command Line: -Xbatch -Xmx1G --add-modules=ALL-DEFAULT jdk.compiler/com.sun.tools.javac.launcher.Main Test.java
..........
Current thread (0x00007f9700341550): JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=6425, stack(0x00007f96e0fcb000,0x00007f96e10cc000)]


Current CompileTask:
C2: 30156 2168 b 4 Test::lMeth (242 bytes)

Stack: [0x00007f96e0fcb000,0x00007f96e10cc000], sp=0x00007f96e10c5f10, free space=1003k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xde6d8f] PhaseIdealLoop::do_peeling(IdealLoopTree*, Node_List&)+0xe5
V [libjvm.so+0xdf2bbf] IdealLoopTree::iteration_split_impl(PhaseIdealLoop*, Node_List&)+0x4f5
V [libjvm.so+0xdf2ce7] IdealLoopTree::iteration_split(PhaseIdealLoop*, Node_List&)+0x10b
V [libjvm.so+0xdf2c18] IdealLoopTree::iteration_split(PhaseIdealLoop*, Node_List&)+0x3c
V [libjvm.so+0xdf2d85] IdealLoopTree::iteration_split(PhaseIdealLoop*, Node_List&)+0x1a9
V [libjvm.so+0xdf2d85] IdealLoopTree::iteration_split(PhaseIdealLoop*, Node_List&)+0x1a9
V [libjvm.so+0xdf2c18] IdealLoopTree::iteration_split(PhaseIdealLoop*, Node_List&)+0x3c
V [libjvm.so+0xe06455] PhaseIdealLoop::build_and_optimize(LoopOptsMode)+0x1517
V [libjvm.so+0x7a9ef5] PhaseIdealLoop::PhaseIdealLoop(PhaseIterGVN&, LoopOptsMode)+0xb3
V [libjvm.so+0x7a9fee] PhaseIdealLoop::optimize(PhaseIterGVN&, LoopOptsMode)+0x46
V [libjvm.so+0x79d5d7] Compile::optimize_loops(PhaseIterGVN&, LoopOptsMode)+0xf7
V [libjvm.so+0x79e4e2] Compile::Optimize()+0xd68
V [libjvm.so+0x79761f] Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x11d9
V [libjvm.so+0x68f3a3] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x15b
V [libjvm.so+0x7b2d0b] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x895
V [libjvm.so+0x7b1997] CompileBroker::compiler_thread_loop()+0x3df
V [libjvm.so+0x11abafe] compiler_thread_entry(JavaThread*, Thread*)+0x69
V [libjvm.so+0x11a7974] JavaThread::thread_main_inner()+0x14c
V [libjvm.so+0x11a7820] JavaThread::run()+0x11e
V [libjvm.so+0x11a3a30] Thread::call_run()+0x180
V [libjvm.so+0xfa1d88] thread_native_entry(Thread*)+0x1e4