. At least on FreeBSD, O_SYNC and O_DSYNC aren't both defined
(for FreeBSD 4.x neither are defined and for FreeBSD 5.x
O_DSYNC isn't defined). This caused them to be defined to
some bogus values. In particular, O_SYNC would be defined
as 0x800, which is O_EXCL (at least on FreeBSD 4.x). The
result being that the RandomAccessFile class would fail to
open an existing file if you specified "s" as part of the mode.
Fix this by defining O_SYNC and O_DSYNC to O_FSYNC if they