* devices.h (device::exists_func): Redefine field.

(device::dev_on_fs): Remove unneeded bit field.  Just make a normal boolean.
(device::exists): Redefine function.
* devices.in: Move previous functions earlier since they are now only defined
static.  Rename some functions due to an as-yet unresolved bug in gendevices.
Rename posix part of internal-only devices with a double-slash.  gendevices
will eventuall translate that to a ":".
(device::parse): Rework to use dev pointer and dev_storage_end.
* devices.cc: Regenerate.
* gendevices: Translate "// to ": after shilka processing.

winsup/cygwin/fhandler_dev.cc

@@ -119,7 +119,10 @@ fhandler_dev::readdir (DIR *dir, dirent *de)
   while (devidx < dev_storage_end)
     {
       const device& thisdev = *devidx++;
-      if (!thisdev.exists ())
+      /* If exists returns < 0 it means that the device can be used by a
+	 program but its use is deprecated and, so, it is not returned
+	 by readdir(().  */
+      if (thisdev.exists () <= 0)
 	continue;
       ++dir->__d_position;
       strcpy (de->d_name, thisdev.name + dev_prefix_len);