Alan Snyder has reported a non-reproducible crash. The crash report is attached.

He says:
I thought I would pass this on in case it is of interest. It is not repeatable. It is on a recent personal build of JDK 9.

Current CompileTask:
C2: 327682 6561 4 javax.swing.JComponent::setEnabled (29 bytes)

Stack: [0x0000000129eb4000,0x0000000129fb4000], sp=0x0000000129fb1b80, free space=1014k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0xbca6f3] VMError::report_and_die(int, char const*, char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long)+0x425
V [libjvm.dylib+0xbcaeb6] VMError::report_and_die(Thread*, char const*, int, char const*, char const*, __va_list_tag*)+0x4a
V [libjvm.dylib+0x47bebb] report_vm_error(char const*, int, char const*, char const*, ...)+0xcd
V [libjvm.dylib+0x354e52] ciEnv::validate_compile_task_dependencies(ciMethod*)+0x1b8
V [libjvm.dylib+0x355564] ciEnv::register_method(ciMethod*, int, CodeOffsets*, int, CodeBuffer*, int, OopMapSet*, ExceptionHandlerTable*, ImplicitExceptionTable*, AbstractCompiler*, bool, bool, RTMState)+0x6da
V [libjvm.dylib+0x41bf32] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool, DirectiveSet*)+0xe32
V [libjvm.dylib+0x41e993] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool, DirectiveSet*)+0x31
V [libjvm.dylib+0x322ba5] C2Compiler::compile_method(ciEnv*, ciMethod*, int, DirectiveSet*)+0x139
V [libjvm.dylib+0x42f01f] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x7bb
V [libjvm.dylib+0x42e528] CompileBroker::compiler_thread_loop()+0x2e0
V [libjvm.dylib+0xb61804] JavaThread::thread_main_inner()+0x1f6
V [libjvm.dylib+0xb6144a] JavaThread::run()+0x3cc
V [libjvm.dylib+0x9cdb02] thread_native_entry(Thread*)+0x12b
C [libsystem_pthread.dylib+0x405a] _pthread_body+0x83
C [libsystem_pthread.dylib+0x3fd7] _pthread_body+0x0
C [libsystem_pthread.dylib+0x13ed] thread_start+0xd