Entirely remove error message for encountering global barriers (previously commented out)

loopy/schedule/__init__.py

@@ -1482,15 +1482,6 @@ def generate_loop_schedules(kernel, debug_args={}):
                     gen_sched = insert_barriers(kernel, gen_sched,
                             reverse=False, kind="global")
 
-                    """
-                    for sched_item in gen_sched:
-                        if (
-                                isinstance(sched_item, Barrier)
-                                and sched_item.kind == "global"):
-                            raise LoopyError("kernel requires a global barrier %s"
-                                    % sched_item.comment)
-                    """
-
                     logger.info("%s: barrier insertion: local" % kernel.name)
 
                     gen_sched = insert_barriers(kernel, gen_sched,