sendmsg.c: Added __objc_msg_forward2...

2007-04-09  Andrew Ruder  <andy@aeruder.net>

        * sendmsg.c: Added __objc_msg_forward2, a hook that allows
        external libraries to provide a function that returns the real
        forwarding function based on both the selector and the receiver.
        * objc/objc-api.h: Define __objc_msg_forward2.

From-SVN: r123678