When running with ubsan-enabled binaries, wee see the error below. This is most likely an issue introduced by JDK-8343782 where the g1RemSetSummary.cpp coding was changed.
jdk tier3 :
java/lang/management/ClassLoadingMXBean/TestVerboseClassLoading.java
java/lang/management/MemoryMXBean/TestVerboseMemory.java

/openjdk-jdk-weekly-linux_ppc64le-opt/jdk/src/hotspot/share/gc/g1/g1RemSetSummary.cpp:344:68: runtime error: member call on null pointer of type 'struct G1HeapRegion'
    #0 0x7fff9806fb18 in HRRSStatsIter::print_summary_on(outputStream*) src/hotspot/share/gc/g1/g1RemSetSummary.cpp:344
    #1 0x7fff9806d430 in G1RemSetSummary::print_on(outputStream*, bool) src/hotspot/share/gc/g1/g1RemSetSummary.cpp:396
    #2 0x7fff9801b35c in G1RemSet::print_summary_info() src/hotspot/share/gc/g1/g1RemSet.cpp:1677
    #3 0x7fff97d91c5c in G1CollectedHeap::print_tracing_info() const src/hotspot/share/gc/g1/g1CollectedHeap.cpp:2175
    #4 0x7fff9844f5a0 in before_exit(JavaThread*, bool) src/hotspot/share/runtime/java.cpp:511
    #5 0x7fff98826910 in JVM_Halt src/hotspot/share/prims/jvm.cpp:429
    #6 0x7fff9e07b8c0 in Java_java_lang_Shutdown_halt0 src/java.base/share/native/libjava/Shutdown.c:41
    #7 0x7fff7b7cd4dc (<unknown module>)