OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       write only
    mechanism:    by value

    The values returned by STR$COMPARE_MULTI and the conditions to
    which they translate are as follows:

    Returned
    Value         Condition

                  first-source-string is less than second-source-
                  string.
    0             Both strings are the same; the shorter string is
                  blank filled.
    1             first-source-string is greater than second-source-
                  string.