[JSR308] Annotations as annotation parameters

[Michael Ernst]

Bill-

> Figure 1 shows:
> @DefaultAnnotation(@NonNull)
> We haven't found anyway to do this with JSR-175 annotations.

You're right; an annotation's parameter can be a specific annotation, but
not an arbitrary one.  Thanks for catching this!

I've reversed that edit to the figure, and added a reference to JLS
sections 9.6 and 9.7.

> Is the ability to do this an extension in JSR-308? I didn't see it  
> spelled out.

No.  An extension that relaxes the JSR 175 limitation would be nice, but I
want to focus on the core parts of JSR 308 first.

                    -Mike