* fhandler.h (class fhandler_base): Change inheritance of fstat_helper

	* fhandler.h (class fhandler_base): Change inheritance of fstat_helper
	and fstat_by_...  methods to private.
	(fhandler_base::fstat_helper): Drop all redundant arguments.
	* fhandler_disk_file.cc (fhandler_base::fstat_by_handle): Drop call
	to fstat_by_nfs_ea here.  Drop fetching basic file information.
	Drop setting file attributes.  Accommodate change in fstat_helper call.
	(fhandler_base::fstat_by_name): Simplify.  Only fetch directory
	information to get the inode number.  Drop setting file attributes.
	Accommodate change in fstat_helper call.
	(fhandler_base::fstat_fs): Call fstat_by_nfs_ea if on NFS.
	(fhandler_base::fstat_helper): Drop all redundant arguments.  Use
	information already collected in the fhandler.  Move heading comment
	into code and drop dwFileAttributes comment.
	* mmap.cc (mmap64): Call fstat_fs rather than fstat_by_handle.
	* mount.cc (fs_info::update): Note that has_buggy_basic_info is unused.
	* path.cc (symlink_info::check_reparse_point): Add comment.
	(symlink_info::check): Fetch FileNetworkOpenInformation rather than
	FileBasicInformation throughout, except on NFS.  Explain why.  Store
	FILE_NETWORK_OPEN_INFORMATION in conv_hdl.  Remove
	FILE_ATTRIBUTE_DIRECTORY attribute in conv_hdl for reparse point
	symlinks.
	* path.h (class path_conv_handle): Add FILE_NETWORK_OPEN_INFORMATION
	member _fnoi.
	(path_conv_handle::fnoi): New accessor method for _fnoi.
	(path_conv::fnoi): New accessor method for cubv_hdl._fnoi.

	* fhandler_tty.cc (fhandler_tty_slave::init): Use tty::setpgid method.