glsl: Add arb_cull_distance support (v3)

v2: make too large array a compile error
v3: squash mesa/prog patch to avoid static compiler errors in bisect

Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>

src/compiler/glsl/link_varyings.h

@@ -210,6 +210,7 @@ private:
    enum {
       none,
       clip_distance,
+      cull_distance,
       tess_level_outer,
       tess_level_inner,
    } lowered_builtin_array_variable;