Add some design time readable metadata for built-in beans of CDI-implementations.

We need such metadata for tooling.
It would be very helpful to have some metadata for beans which implement spec required services (BeanManager, ...)
Or for any other beans which CDI implementations register programmatically and which should be available for users.
For example Weld loads some beans from jars which don't have beans.xml but some of those beans are available for injections.
So far we don't have any documented way to recognize such beans.