Summary: Set the property on the command line as the JDK 11 version
Reviewed-by: clanger, andrew, chegar

Reviewed-by: alanb, dsamersoff

6964714: NetworkInterface getInetAddresses enumerates IPv6 addresses if java.net.preferIPvStack property set
Summary: User can disable ipv6 explicitly, have to check it
Reviewed-by: chegar, alanb

Reviewed-by: darcy, weijun

Summary: move the test cases to openjdk
Reviewed-by: martin