While testing the new -XX:+StressUnstableIfTraps option (see JDK-8335334), I hit an assert with TestDuplicatedLateInliningOutput.java added by JDK-8320237. I slightly modified the test (see attached test.patch) and can now also reproduce the issue without any stress options:

# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/open/src/hotspot/share/opto/compile.cpp:4582), pid=317975, tid=317990
# assert(_print_inlining_stream->size() > 0) failed: missing inlining msg
#
# JRE version: Java(TM) SE Runtime Environment (24.0+4) (fastdebug build 24-ea+4-328)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 24-ea+4-328, mixed mode, sharing, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0x9d4336] Compile::print_inlining_update_delayed(CallGenerator*)+0x1c6

Current CompileTask:
C2:103 7 b compiler.inlining.TestDuplicatedLateInliningOutput$NonConstantReceiverLauncher::test (16 bytes)

Stack: [0x00007ff401638000,0x00007ff401739000], sp=0x00007ff401734140, free space=1008k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x9d4336] Compile::print_inlining_update_delayed(CallGenerator*)+0x1c6 (compile.cpp:4582)
V [libjvm.so+0x83b675] CallGenerator::do_late_inline_helper()+0x9a5
V [libjvm.so+0x9da9b4] Compile::inline_incrementally_one()+0xd4
V [libjvm.so+0x9db288] Compile::process_late_inline_calls_no_inline(PhaseIterGVN&)+0x78
V [libjvm.so+0x9de404] Compile::Optimize()+0x1024
V [libjvm.so+0x9e1946] Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x1b06
V [libjvm.so+0x833955] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x1d5
V [libjvm.so+0x9ed5b8] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x928
V [libjvm.so+0x9ee248] CompileBroker::compiler_thread_loop()+0x478
V [libjvm.so+0xe97a1c] JavaThread::thread_main_inner()+0xcc
V [libjvm.so+0x17b4b76] Thread::call_run()+0xb6
V [libjvm.so+0x149e2d7] thread_native_entry(Thread*)+0x127

Looks like a regression from JDK-8335334. At least, when reverting JDK-8335334 the issue does not reproduce anymore.