pgsql: Fix get_dirent_type() for Windows junction points.

Fix get_dirent_type() for Windows junction points.

Commit 87e6ed7c8 added code that intended to report Windows "junction
points" as DT_LNK (the same way we report symlinks on Unix). Windows
junction points are *also* directories according to the Windows
attributes API, and we were reporting them as as DT_DIR. Change the
order we check the attribute flags, to prioritize DT_LNK.

If at some point we start using Windows' recently added real symlinks
and need to distinguish them from junction points, we may need to
rethink this, but for now this continues the tradition of wrapper
functions that treat junction points as symlinks.

Back-patch to 14, where get_dirent_type() landed.

Reviewed-by: Michael Paquier <michael(at)paquier(dot)xyz>
Reviewed-by: Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
Discussion: https://postgr.es/m/CA%2BhUKGLzLK4PUPx0_AwXEWXOYAejU%3D7XpxnYE55Y%2Be7hB2N3FA%40mail.gmail.com
Discussion: https://postgr.es/m/20220721111751.x7hod2xgrd76xr5c%40alvherre.pgsql

Branch
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REL_15_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/6d306ab731689ca01cdcafda9862732dcc075778

Modified Files
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src/port/dirent.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)