mesa: enable ARB_direct_state_access in compat for GL3.1+

We could enable it for lower versions of GL but this allows us
to just use the existing version/extension checks that are already
used by the core profile.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/mesa/main/arrayobj.c

@@ -196,7 +196,16 @@ _mesa_vao_attribute_map[ATTRIBUTE_MAP_MODE_MAX][VERT_ATTRIB_MAX] =
 struct gl_vertex_array_object *
 _mesa_lookup_vao(struct gl_context *ctx, GLuint id)
 {
+   /* The ARB_direct_state_access specification says:
+    *
+    *    "<vaobj> is [compatibility profile:
+    *     zero, indicating the default vertex array object, or]
+    *     the name of the vertex array object."
+    */
    if (id == 0) {
+      if (ctx->API == API_OPENGL_COMPAT)
+         return ctx->Array.DefaultVAO;
+
       return NULL;
    } else {
       struct gl_vertex_array_object *vao;