Previously, dual stack UDP sockets bound to an IPv4 address could not use
sendto to communicate with IPv4 addresses. Further, dual stack UDP sockets
bound to an IPv6 address could use sendto to communicate with IPv4 addresses.
Neither of these behaviors are consistent with Linux.
PiperOrigin-RevId: 197036024
Change-Id: Ic3713efc569f26196e35bb41e6ad63f23675fc90
Tamir Duberstein
Ian Gudger
Nicolas Lacasse
Googler