Check for internal IPv6 connects and extends
In teor's comment in #31088 (moved):
You've added some code that isn't needed yet. Please reject all IPv6 extends in this patch, and open a separate child ticket of #24403 (moved) for allowing IPv6 extends.
Edited to add:
When we add support for IPv6 extends, we should check for internal IPv6 addresses in extends. And we should check for internal IPv6 connects on non-bridge clients, relays, and authorities.
ExtendAllowPrivateAddresses should disable these new checks.