default methods reuse in Proxy

[Olexandr Demura]

Is it possible to call default implementation of method for Proxy?
So far default`ed methods handled thru InvocationHandler as well even
they are not marked abstract.
I do not see which way can default implementation be called, since:
- their `getDefaultValue()` gives `null`, unlike @annotation's.
- there is no additional statics method in class w/ added first
parameter for `this`.
Is it planned to hide or will be changed to be accessible?

BTW, why we still need to write `default`?
especially since only in-line defaulting style is supported now.