In CI tier 2 and 3 testing on all platforms:

# assert(JdkJfrEvent::is(klass)) failed: invariant

Current thread (0x00007f10b001a800): JavaThread "main" [_thread_in_vm, id=15523, stack(0x00007f10bb06c000,0x00007f10bb16d000)]

Stack: [0x00007f10bb06c000,0x00007f10bb16d000], sp=0x00007f10bb16a940, free space=1018k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x1864073] VMError::report_and_die(int, char const*, char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long)+0x2c3
V [libjvm.so+0x1864e8f] VMError::report_and_die(Thread*, void*, char const*, int, char const*, char const*, __va_list_tag*)+0x2f
V [libjvm.so+0xb12860] report_vm_error(char const*, int, char const*, char const*, ...)+0x100
V [libjvm.so+0xed54db] JfrEventClasses::get_all_event_classes(Thread*)+0x78b
V [libjvm.so+0xee8e51] jfr_get_all_event_classes+0x141
j jdk.jfr.internal.JVM.getAllEventClasses()Ljava/util/List;+0 jdk.jfr@12-internal
j jdk.jfr.internal.MetadataRepository.unregisterUnloaded()V+24 jdk.jfr@12-internal
j jdk.jfr.internal.MetadataRepository.setOutput(Ljava/lang/String;)V+8 jdk.jfr@12-internal
j jdk.jfr.internal.PlatformRecorder.start(Ljdk/jfr/internal/PlatformRecording;)V+135 jdk.jfr@12-internal
j jdk.jfr.internal.PlatformRecording.start()V+65 jdk.jfr@12-internal
j jdk.jfr.Recording.start()V+4 jdk.jfr@12-internal
j jdk.jfr.internal.dcmd.DCmdStart.execute(Ljava/lang/String;[Ljava/lang/String;Ljava/lang/Long;Ljava/lang/Long;Ljava/lang/Boolean;Ljava/lang/String;Ljava/lang/Long;Ljava/lang/Long;Ljava/lang/Boolean;Ljava/lang/Boolean;)Ljava/lang/String;+701 jdk.jfr@12-internal
v ~StubRoutines::call_stub
V [libjvm.so+0xe8befa] JavaCalls::call_helper(JavaValue*, methodHandle const&, JavaCallArguments*, Thread*)+0x85a
V [libjvm.so+0xe8777a] JavaCalls::call_virtual(JavaValue*, Klass*, Symbol*, Symbol*, JavaCallArguments*, Thread*)+0x31a
V [libjvm.so+0xedb9a0] JfrJavaCall::call_virtual(JfrJavaArguments*, Thread*)+0x300
V [libjvm.so+0xec420d] JfrStartFlightRecordingDCmd::execute(DCmdSource, Thread*)+0xb9d
V [libjvm.so+0xf155c3] JfrRecorder::on_vm_start()+0x4f3
V [libjvm.so+0xeb1229] Jfr::on_vm_start()+0x9
V [libjvm.so+0x1798b3a] Threads::create_vm(JavaVMInitArgs*, bool*)+0x77a
V [libjvm.so+0xfac4ea] JNI_CreateJavaVM+0x6a
C [libjli.so+0x3fe6] JavaMain+0x86

Seems to have been caused by JDK-8203629