RFR 8163083: SocketListeningConnector does not allow invocations with port 0

[Daniil Titov]

Please review the change that fixes the issue in com.sun.tools.jdi.SocketListenerConnector.startListening() method.

When the argument map passed to startListening() methods has the port number unspecified or set to zero the port is auto detected. However,  the consequent call of startListening() methods with unspecified port number fails rather than starts a new listener on auto detected port. This happens since the original argument map passed to the startListening() methods is used as a key to store the mapping to the started listeners.

The fix ensures that in cases when the port is auto detected the argument map is updated with the bound port number. 

Mach5 vmTestbase_nsk_jdi tests successfully passed. 

Bug: https://bugs.openjdk.java.net/browse/JDK-8163083 
Webrev: http://cr.openjdk.java.net/~dtitov/8163083/webrev.02/

Thanks!
--Daniil