Enable Some DRI Support for Radeon HD 4850

[Jason C. Wells]

My video card is a radeon HD 4850 which would use the r600_dri.so 
module, if one was installed.  The fallback module is swrast_dri.so.  I 
am using the radeon driver in xorg.conf.  Running 8.2-RELEASE with 
mostly 8.2-R ports.

Is there a way that I can get _some_ 3D hardware support?  I don't need 
it to be perfect.  I'd like celestia to run a bit faster than dog slow. 
Perhaps I can manually force a module that somewhat supports the HD 4850.

I tried faking out the automagic system by 'ln -s r300_dri.so 
r600_dri.so' but that didn't work.  r300 was unable to identify the chip 
and so fallback to the swrast_dri.so module occurred.

I've looked into updating graphics/dri to 7.11.2, but that is turning 
out to be an effort in tracking down and tweaking a lot of dependencies.

Thanks,
Jason C. Wells