WSADuplicateSocket is useful to pass sockets between processes on
Windows.

For golang/go#10350.

Change-Id: I6563184fe4d4477d402a6af81b254bd8aa992d2e
Reviewed-on: https://go-review.googlesource.com/c/sys/+/668215
Reviewed-by: Damien Neil <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Carlos Amedee <[email protected]>