DCX$_INVCTX        Error. The context variable is invalid, or the
                       context area is invalid or corrupted. This may
                       be caused by a failure to call the appropriate
                       routine to initialize the context variable or
                       by an application program error.
    DCX$_NORMAL        Normal successful completion.

    This routine also returns any condition values returned by
    LIB$ANALYZE_SDESC_R2.