When running ubsan-enabled optimized binaries on Linux x86_64, test
compiler/startup/StartupOutput.java
triggers this ubsan issue :

jdk/src/hotspot/share/ci/ciEnv.cpp:1660:65: runtime error: member call on null pointer of type 'struct CompileTask'
    #0 0x7fe7443fc88d in ciEnv::dump_replay_data_helper(outputStream*) src/hotspot/share/ci/ciEnv.cpp:1660
    #1 0x7fe746c22047 in VMError::report_and_die(int, char const*, char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long) src/hotspot/share/utilities/vmError.cpp:1872
    #2 0x7fe7447dd429 in report_fatal(VMErrorType, char const*, int, char const*, ...) src/hotspot/share/utilities/debug.cpp:214
    #3 0x7fe7445c614d in RuntimeStub::new_runtime_stub(char const*, CodeBuffer*, short, int, OopMapSet*, bool, bool) src/hotspot/share/code/codeBlob.cpp:413
    #4 0x7fe744259ceb in Runtime1::generate_blob(BufferBlob*, int, char const*, bool, StubAssemblerCodeGenClosure*) src/hotspot/share/c1/c1_Runtime1.cpp:230
    #5 0x7fe74425a273 in Runtime1::generate_blob_for(BufferBlob*, Runtime1::StubID) src/hotspot/share/c1/c1_Runtime1.cpp:259
    #6 0x7fe74425a273 in Runtime1::initialize(BufferBlob*) src/hotspot/share/c1/c1_Runtime1.cpp:268
    #7 0x7fe743fc04a1 in Compiler::init_c1_runtime() src/hotspot/share/c1/c1_Compiler.cpp:53
    #8 0x7fe743fc04a1 in Compiler::initialize() src/hotspot/share/c1/c1_Compiler.cpp:74
    #9 0x7fe7446aaad7 in CompileBroker::init_compiler_runtime() src/hotspot/share/compiler/compileBroker.cpp:1771
    #10 0x7fe7446b83cf in CompileBroker::compiler_thread_loop() src/hotspot/share/compiler/compileBroker.cpp:1913
    #11 0x7fe74516edca in JavaThread::thread_main_inner() src/hotspot/share/runtime/javaThread.cpp:758
    #12 0x7fe7469d3c9a in Thread::call_run() src/hotspot/share/runtime/thread.cpp:225
    #13 0x7fe746048cd1 in thread_native_entry src/hotspot/os/linux/os_linux.cpp:858
    #14 0x7fe74b1e66e9 in start_thread (/lib64/libpthread.so.0+0xa6e9) (BuildId: 052f7e2a0045f08cb7e7a291f8066a4b7be2521d)
    #15 0x7fe74aaf158e in clone (/lib64/libc.so.6+0x11858e) (BuildId: cfb059a57e69ac95d5dadab831626b3bd48a4309)