This involved wrapping some GCOps to get the proper behavior
when using X11 raster ops mixed with OpenGL (see driWrap.c).
This extends the AppleDRI protocol with create and destroy pixmap
functions.
The dri.c code has been extended quite a bit to enable this, and
to initialize the wrapping of CreateGC for GCOps.
This has been tested with tests/glxpixmap and proven to work with
the new libGL. Existing applications seem to work fine too. Redraws
all appear to be correct.
There may be some bugs lurking that I haven't found yet. I plan
to drive them out by extending the libGL test suite.
(cherry picked from commit 630518766b)
