[11u] RFR: 8228434: jdk/net/Sockets/Test.java fails after JDK-8227642

[Langer, Christoph]

Hi,

please review the backport of this test fix which shall be brought to JDK11 updates together with "JDK-8227642 [TESTBUG] Make docker tests podman compatible".

The reported test failure would not occur in JDK11u, but this change does no harm and can help to avoid issues should other test changes be backported that rely on this fix.

After applying the original patch, I had to resolve test/jdk/TEST.ROOT manually and also had to manually fit the hunk in test/lib/jdk/test/lib/Platform.java.

Bug: https://bugs.openjdk.java.net/browse/JDK-8228434
Original Change: https://hg.openjdk.java.net/jdk/jdk/rev/07e998f8f816
11u-Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8228434.11u-dev.0/

Thanks
Christoph