The defining class loader of java.xml.ws, java.xml.bind, and java.activation
module and their classes is changed to the platform class loader (non-null)
(see the specification for `java.lang.ClassLoader::getPlatformClassLoader`).

Existing code that assumes the defining class loader of JAX-WS, JAXB, JAF
classes may be impacted by this change (e.g. custom class loader delegation to
the bootstrap class loader skipping the extension class loader).