[xf86-video-ati] crash with latest code from git (possibly radeon-rewrite related)

[Lowell Alleman]

I've run into an X server crash with the latest radeon driver from
git, packaged for Ubuntu Jaunty by Tormod Volden.  I'm also using the
radeon-rewrite mesa branch, which I have been using for a few weeks
now, however this bug seems to be related to my recent upgrade of the
xf86-video-ati driver.  (I have not attempted to rollback the driver
to confirm this.)