RPGLE - Clear messages subfile API

    RPGLE  - Clear messages subfile API

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      *    $ClrMsg - clear the messages from the screen
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     C     $ClrMsg       begsr
      *
     C                   call      'QMHRMVPM'
     C                   parm                    PGMQ
     C                   parm                    STKCNT
     C                   parm                    MSGKY
     C                   parm                    MSGRMV
     C                   parm                    ERRCOD
      *
     C                   endsr