Ping [Patch] include/coff/xcoff.h: add new macros

[Richard Sandiford]

Hi Tristan,

Sorry to show my ignorance, but where did you get these macro
definitions from?  I only have access to the public documentation
and can't find definitions for some of these.

I trust you that they're correct.  The reason I held back was that
I was worried about copyright issues if the patch was a bulk copy of
macros from the AIX header files.

Richard