Terminates a link between two ICC associations.
    The $ICC_DISCONNECTW service completes synchronously; that is,
    it returns to the caller after the connection has completely
    finished the disconnection request.
    For asynchronous completion, use the $ICC_DISCONNECT service;
    $ICC_DISCONNECT returns to the caller as soon as the
    disconnection request has been sent to the transport layer,
    without waiting for notification that the disconnection has
    completed.
    On Alpha and Integrity server systems, this service accepts 64-
    bit addresses.
    Format
      SYS$ICC_DISCONNECTW  conn_handle ,iosb ,[astadr] ,[astprm]
                           ,[disc_buf] ,[disc_buf_len]
    C Prototype
      int sys$icc_disconnectw  (unsigned int conn_handle,
                               struct _iosb, *iosb, void
                               (*astadr)(__unknown_params), __int64
                               astprm, char * disc_buf, unsigned int
                               disc_buf_len);