IN  PIRP_CONTEXT IrpContext,
  IN  ULONG DirentOffset,
  OUT PWCHAR ShortFileName,
  OUT PUSHORT ShortByteCount

Routine Description:

    This routine is called to generate a short name from the given long name.  We will
    generate a short name from the given long name.

    We go through the following steps to make this conversion.

        1 - Generate the generic short name.  This will also be in unicode format.

        2 - Build the string representation of the dirent offset.

        3 - Build the biased short name string by combining the generic short name with
            the dirent offset string.

        4 - Copy the final unicode string back to our caller's buffer.


    FileName - String of bytes containing the name.

    DirentOffset - Offset in the directory for this filename.  We incorporate the offset into
        the short name by dividing this by 32 and prepending a tilde character to the
        digit character.  We then append this to the base of the generated short name.

    ShortFileName - Pointer to the buffer to store the short name into.

    ShortByteCount - Address to store the number of bytes in the short name.

Return Value: