(so) ServerSocketChannel::supportedOptions includes IP_TOS

An issue with ServerSocketChannel::supportedOptions including the IP_TOS socket is reported here.
  http://mail.openjdk.java.net/pipermail/nio-dev/2018-August/005365.html

It seems that the ServerSocketChannel has had partial support for IP_TOS since JDK 8u40 as a result of JDK- 8029607. The option can be set but cannot be read. The references to IP_TOS should be removed from ServerSocketChannelImpl.

The following test, maybe test/jdk/java/nio/channels/etc/PrintSupportedOptions.java demonstrates the issue:

/**
 * @test
 * @run PrintSupportedOptions
 * @run main/othervm -Djava.net.preferIPv4Stack=true PrintSupportedOptions
 *

import java.io.IOException;
import java.net.SocketOption;
import java.nio.channels.DatagramChannel;
import java.nio.channels.NetworkChannel;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;

public class PrintSupportedOptions {

    @FunctionalInterface
    interface NetworkChannelSupplier<T extends NetworkChannel> {
        T get() throws IOException;
    }

    public static void main(String[] args) throws IOException {
        test(() -> SocketChannel.open());
        test(() -> ServerSocketChannel.open());
        test(() -> DatagramChannel.open());
    }

    static void test(NetworkChannelSupplier supplier) throws IOException {
        try (NetworkChannel ch = supplier.get()) {
            System.out.println(ch);
            for (SocketOption<?> opt : ch.supportedOptions()) {
                System.out.format(" %s -> %s%n", opt.name(), ch.getOption(opt));
            }
        }
    }
}