mesa: Add Get* support for ARB_vertex_attrib_binding

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
diff --git a/src/mesa/main/varray.c b/src/mesa/main/varray.c
index b0e0286..39e5ad3 100644
--- a/src/mesa/main/varray.c
+++ b/src/mesa/main/varray.c
@@ -747,6 +747,16 @@
          return arrayObj->VertexBinding[array->VertexBinding].InstanceDivisor;
       }
       goto error;
+   case GL_VERTEX_ATTRIB_BINDING:
+      if (_mesa_is_desktop_gl(ctx)) {
+         return array->VertexBinding - VERT_ATTRIB_GENERIC0;
+      }
+      goto error;
+   case GL_VERTEX_ATTRIB_RELATIVE_OFFSET:
+      if (_mesa_is_desktop_gl(ctx)) {
+         return array->RelativeOffset;
+      }
+      goto error;
    default:
       ; /* fall-through */
    }