win32: optimize parameters for the CreateFile call in _getfileinfo
Set dwDesiredAccess to 0 instead of GENERIC_READ.
Zero is enough for querying the file metadata. We don't even need to
access the -contents- of the file.
Set dwShareMode to FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE
instead of the overly restrictive FILE_SHARE_READ.
There is no need to cause write or delete accesses by other processes to
fail while we are querying file metadata.
See http://msdn.microsoft.com/en-us/library/
aa363858(v=vs.85).aspx