hg: jdk/submit: 8241786: Improve heuristic to determine default network interface on macOS

[daniel.fuchs at oracle.com]

Changeset: 70175514ffa1
Author:    dfuchs
Date:      2020-04-03 14:27 +0100
URL:       https://hg.openjdk.java.net/jdk/submit/rev/70175514ffa1

8241786: Improve heuristic to determine default network interface on macOS
Summary: DefaultInetrface.getDefault is updated to prefer interfaces that have non link-local addresses. NetworkConfiguration is updated to skip interface that have only link-local addresses, whether IPv4 or IPv6, for multicasting.
Reviewed-by: chegar, alanb

! src/java.base/macosx/classes/java/net/DefaultInterface.java
! test/jdk/java/net/MulticastSocket/SetLoopbackMode.java
! test/jdk/java/net/MulticastSocket/SetLoopbackModeIPv4.java
! test/jdk/java/net/MulticastSocket/SetOutgoingIf.java
! test/jdk/java/nio/channels/DatagramChannel/AdaptorMulticasting.java
! test/jdk/java/nio/channels/DatagramChannel/MulticastSendReceiveTests.java
! test/jdk/java/nio/channels/DatagramChannel/Promiscuous.java
! test/lib/jdk/test/lib/NetworkConfiguration.java