On Alpha systems, returns information about the exception context
    for a given arithmetic exception. There are two forms the signal
    argument vectors: one for use with 32-bit addresses and one for
    use with 64-bit addresses.

    For more information, see the section "Signal Argument Vector" in
    the VSI OpenVMS Calling Standard.

    Format

      SYS$GET_ARITH_EXCEPTION  sigarg ,mcharg ,buffer

    C Prototype

      int sys$get_arith_exception  (void *sigarg, void *mcharg, void

                                   *buffer);