Use is test, to not trigger __eq__.

Author: miracle2k

trio_asyncio/util.py

@@ -76,7 +76,7 @@ def abort_cb(raise_cancel_arg):
             asyncio.ensure_future(consume_next(), loop=loop)
 
             item = await trio.hazmat.wait_task_rescheduled(abort_cb)
-            if item == STOP:
+            if item is STOP:
                 break
             yield item