G++ knowledge of multiple-inheritance class

[David Edelsohn]

	Is there any way for a GCC port to know that a function call is to
a multiple-inheritance class?  More specifically, know that a call through
a virtual function table will be to a thunk (assuming thunks are enabled)
as opposed to any other indirect call through a pointer?  With this
knowledge, AIX thunk calls could be much more efficient.

Thanks, David