Add a portable implementation for IsDir(). dirent.d_type is not in POSIX and does not exist at least on Solaris.
Add a portable implementation for IsDir().
dirent.d_type is not in POSIX and does not exist at least on Solaris.

ooyamams/pg_rman,ooyamams/pg_rman,bwtakacy/prev_pg_rman_repo,bwtakacy/prev_pg_rman_repo