support IOLoop.close() when called after asyncio.run about tornado HOT 1 OPEN

My assumption has been that you wouldn't mix IOLoop and asyncio event loop control methods in the same app: you could use IOLoop.run_sync instead of asyncio.run, but in that case you'd rely on the asyncio lifecycle instead of Tornado's. Asyncio doesn't have an all_fds=True equivalent, but I'd expect that if you're relying on that you'd use the ioloop methods instead of asyncio.run. Is there some reason you can't either use the IOLoop methods here or avoid relying on all_fds=True? (If you need this functionality we should look into getting it added to asyncio - I want to eventually phase out all usage of IOLoop)

from tornado.