* dtable.cc (dtable::build_fhandler_from_name): Set some fhandler

data on sockets to evaluate AF_LOCAL sockets correctly.
	(dtable::build_fhandler): Set unit number on sockets.
	* fhandler.h (fhandler_socket): Add unit number.
	(fhandler_socket::get_unit): New method.
	* fhandler_socket.cc (fhandler_socket::fhandler_socket): Set unit
	number.
	(fhandler_socket::fstat): Reorganize to return more Linux-like
	values.
	* net.cc: include ctype.h.
	(fdsock): Set unit number when building fhandler.
	* path.cc (path_conv::check): Set device type to FH_SOCKET if file
	is a AF_UNIX socket.
	(get_devn): Evaluate unit for virtual socket devices.
	(win32_device_name): Set windows path for sockets to unix_path with
	just backslashes to keep the different names.
	* syscalls.cc (fstat64): Don't override st_ino, st_dev and st_rdev
	for sockets.
	(stat_worker): Ditto.

From Pierre Humblet:

	* autoload.cc (AccessCheck): Add.
	(DuplicateToken): Add.
	* security.h (check_file_access): Declare.
	* syscalls.cc (access): Convert path to Windows, check existence
	and readonly attribute. Call check_file_access instead of acl_access.
	* security.cc (check_file_access): Create.
	* sec_acl (acl_access): Delete.

winsup/cygwin/fhandler.h

@@ -385,12 +385,14 @@ class fhandler_socket: public fhandler_base
   struct _WSAPROTOCOL_INFOA *prot_info_ptr;
   char *sun_path;
   int had_connect_or_listen;
+  int unit;
 
  public:
-  fhandler_socket ();
+  fhandler_socket (int unit);
   ~fhandler_socket ();
   int get_socket () { return (int) get_handle(); }
   fhandler_socket * is_socket () { return this; }
+  int get_unit () { return unit; }
 
   bool saw_shutdown_read () const {return FHISSETF (SHUTRD);}
   bool saw_shutdown_write () const {return FHISSETF (SHUTWR);}