8182731: Odd handling of -XX:-UseAppCDS and -XX:SharedArchiveFile
Application class data sharing is enabled without -XX:+UseAppCDS. SharedArchiveFile is now a product flag.
Reviewed-by: dholmes, ihse, erikj, ccheung
Check file names in a directory. It is empty if only the "." and ".." files exist. Use unicode version of windows APIs to handle long path.
Reviewed-by: iklam, sspitsyn
