bpo-27929: resolve names only for AF_INET/AF_INET6 with asyncio

[vincentbernat]

For other families, it may not make sense to resolve names. For
example, with AF_BLUETOOTH, there is no name resolution and attempting
to do so will trigger a "ai_family not supported".

The bug report contains an example:

import asyncio
import socket
sock = socket.socket(family=socket.AF_BLUETOOTH,
                     type=socket.SOCK_STREAM,
                     proto=socket.BTPROTO_RFCOMM)
sock.setblocking(False)
addr = "00:12:34:56:78:99"
loop = asyncio.get_event_loop()
loop.run_until_complete(loop.sock_connect(sock, (addr, 1)))

https://bugs.python.org/issue27929

https://bugs.python.org/issue27929

[the-knights-who-say-ni]

Hello, and thanks for your contribution!

I'm a bot set up to make sure that the project can legally accept this contribution by verifying everyone involved has signed the PSF contributor agreement (CLA).

CLA Missing

Our records indicate the following people have not signed the CLA:

@vincentbernat

For legal reasons we need all the people listed to sign the CLA before we can look at your contribution. Please follow the steps outlined in the CPython devguide to rectify this issue.

If you have recently signed the CLA, please wait at least one business day
before our records are updated.

You can check yourself to see if the CLA has been received.

Thanks again for the contribution, we look forward to reviewing it!

[asvetlov]

1. Please add NEWS entry (https://devguide.python.org/#quick-reference point 8)
2. Python can be compiled without IPv6 support, socket.AF_INET6 is not available. Please use base_events._HAS_IPv6.

[bedevere-bot]

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

[miss-islington]

Thanks @vincentbernat for the PR, and @asvetlov for merging it 🌮🎉.. I'm working now to backport this PR to: 3.9, 3.10.
🐍🍒⛏🤖

[asvetlov]

Thanks!

[bedevere-bot]

GH-32164 is a backport of this pull request to the 3.10 branch.

[bedevere-bot]

GH-32165 is a backport of this pull request to the 3.9 branch.