[cairo] Render EXTEND_REPEAT bug is back...

[Vladimir Vukicevic]

It looks like that the ati/radeon driver is hit by the old  
'buggy_repeat' bug, even with a new X server.  I've got Xorg 1.4.0.90,  
radeon driver 6.7.197 and a more recent one built from git yesterday;  
both show the bug.  (Tested with https://bugzilla.mozilla.org/show_bug.cgi?id=41358.)

Any thoughts on what we can do about this?  Is there a way to grab the  
name/version of the currently in-use display driver for a given  
display with some Xorg extension?  Ideally this would get fixed in the  
radeon driver, but this bug is present in the most recent shipping  
linux distros; unless they were all willing to backport and release an  
update, we may still need a workaround.

     - Vlad