Simplify and clean up GLX visual initialization.

Instead of the fragile setup where we filter the modes common between the
DDX generated GLX visuals and the DRI driver generated fbconfigs, we now
just take the fbconfigs returned by the DRI driver to be our supported set.

hw/xnest/Screen.c

@@ -45,10 +45,6 @@ is" without express or implied warranty.
 Window xnestDefaultWindows[MAXSCREENS];
 Window xnestScreenSaverWindows[MAXSCREENS];
 
-#ifdef GLXEXT
-extern void GlxWrapInitVisuals(miInitVisualsProcPtr *);
-#endif
-
 static int xnestScreenGeneration = -1;
 
 ScreenPtr
@@ -230,17 +226,6 @@ xnestOpenScreen(int index, ScreenPtr pScreen, int argc, char *argv[])
   defaultVisual = visuals[xnestDefaultVisualIndex].vid;
   rootDepth = visuals[xnestDefaultVisualIndex].nplanes;
 
-#ifdef GLXEXT
-  {
-    miInitVisualsProcPtr proc = NULL;
-
-    GlxWrapInitVisuals(&proc);
-    /* GlxInitVisuals ignores the last three arguments. */
-    proc(&visuals, &depths, &numVisuals, &numDepths,
-	 &rootDepth, &defaultVisual, 0, 0, 0);
-  }
-#endif
-
   if (xnestParentWindow != 0) {
     XGetWindowAttributes(xnestDisplay, xnestParentWindow, &gattributes);
     xnestWidth = gattributes.width;