-Wnonnull happens in classLoaderData.inline.hpp

In file included from /home/ysuenaga/git-forked/jdk/src/hotspot/share/utilities/globalDefinitions.hpp:29,
                 from /home/ysuenaga/git-forked/jdk/src/hotspot/share/memory/allocation.hpp:29,
                 from /home/ysuenaga/git-forked/jdk/src/hotspot/share/classfile/classLoaderData.hpp:28,
                 from /home/ysuenaga/git-forked/jdk/src/hotspot/share/precompiled/precompiled.hpp:34:
In member function 'oop ClassLoaderData::class_loader() const',
    inlined from 'void Dictionary::verify()' at /home/ysuenaga/git-forked/jdk/src/hotspot/share/classfile/dictionary.cpp:635:3:
/home/ysuenaga/git-forked/jdk/src/hotspot/share/classfile/classLoaderData.inline.hpp:37:50: warning: 'this' pointer is null [-Wnonnull]
   37 | assert(_holder.is_null() || holder_no_keepalive() != NULL , "This class loader data holder must be alive");
      | ~~~~~~~~~~~~~~~~~~~^~