[release-branch.go1.25] net: fix WriteMsgUDPAddrPort addr handling on IPv4 sockets
Accept IPv4-mapped IPv6 destination addresses on IPv4 UDP sockets.
Fixes #74999.
Change-Id: I4624b9b8f861aedcae29e51d5298d23ce1c0f2c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/689976
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Mark Freeman <markfreeman@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
(cherry picked from commit
bdb2d50fdf40706e7d7411f33ade80edac726707)
Reviewed-on: https://go-review.googlesource.com/c/go/+/695875
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>