Virtual function call writeup

[Jim Dehnert]

Thanks to Mark for the writeup, and to Christophe and Jason for the
examples from the meeting.  I've done a couple things:

 1) I've added the examples to the abi-examples.html document,
    along with an implementation discussion (written before I saw
    Mark's, so that's not integrated, though I intend to).

 2) I've largely replaced the calling convention discussion in the
    abi-layout.html document with Mark's description, leaving in a
    bit of the old stuff that supplements what Mark wrote.

Take a look at these, please, and send your comments.

Jim
-	    Jim Dehnert		dehnert at sgi.com
				(650)933-4272