8246143: UnreferencedXXX tests fail when run with --illegal-access=deny

This patch updates the @modules tag with +open in the tests UnreferencedDatagramSockets and UnreferncedMulticastSockets in advance of the removal of --illegal-access to allow access to private member fields required by the tests.

Reviewed-by: alanb, dfuchs

Author: c-cleary

test/jdk/java/net/DatagramSocket/UnreferencedDatagramSockets.java

@@ -25,7 +25,7 @@
  * @test
  * @library /test/lib
  * @modules java.management java.base/java.io:+open java.base/java.net:+open
- *          java.base/sun.net
+ *          java.base/sun.net java.base/sun.nio.ch:+open
  * @run main/othervm UnreferencedDatagramSockets
  * @run main/othervm -Djava.net.preferIPv4Stack=true UnreferencedDatagramSockets
  * @run main/othervm -Djdk.net.usePlainDatagramSocketImpl UnreferencedDatagramSockets

test/jdk/java/net/MulticastSocket/UnreferencedMulticastSockets.java

@@ -25,7 +25,7 @@
  * @test
  * @library /test/lib
  * @modules java.management java.base/java.io:+open java.base/java.net:+open
- *          java.base/sun.net
+ *          java.base/sun.net java.base/sun.nio.ch:+open
  * @run main/othervm -Djava.net.preferIPv4Stack=true UnreferencedMulticastSockets
  * @run main/othervm -Djdk.net.usePlainDatagramSocketImpl UnreferencedMulticastSockets
  * @run main/othervm UnreferencedMulticastSockets