Generate metadata for non-public base classes

[slavchev]

In Java it is possible to call public method of non-public base class. Here is an example:

class Base {
   public void method1() {
   }
}
public class Derived extends Base {
   public void method2() {
   }
}
...
Derived d = new Derived();
d.method1();
d.method2();

Currently the metadata generator doesn't generate metadata for Base.method1.

[slavchev]

ping @nikolay-diyanov