Repair the synonym and reverse address mapping links for nodes in a
 directory service.

     REPAIR [DECNET] NODE node-name
         [ DIRECTORY_SERVICE dir-service ]
         [ REVERSE_DIRECTORY rev-dir-name ]
         [ SYNONYM_DIRECTORY syn-dir-name ]

 This is used when a node's synonym and reverse address mapping links are
 accidentally deleted or otherwise changed to that they no longer map to
 the correct node name.  To determine whether or not a node's synonym and
 reverse address mapping links are correct, use the SHOW command with the
 FULL keyword.