This change makes gobind to generate proper Go-side proxy code to
handle interface methods that have parameters and return values.
It allows gobind to accept struct pointer types as parameters
or a return value of a method.
Fixesgolang/go#9487, golang/go#9488.
Change-Id: Id243c42ee0701d40e3871e392140368c2f8f9bc6
Reviewed-on: https://go-review.googlesource.com/2348
Reviewed-by: David Crawshaw <crawshaw@golang.org>
