clear fi_future in python throw/close

Author: msullivan

Lib/asyncio/futures.py

@@ -324,9 +324,11 @@ def send(self, v, /):
         return self.__gen.send(v)
 
     def throw(self, *args):
+        self.fi_future = None
         return self.__gen.throw(*args)
 
     def close(self):
+        self.fi_future = None
         self.__gen.close()