* external.cc (cygwin_internal): Make v1 mount table access invalid.

* path.cc (mount_info::init): Remove had_to_create_mount_areas initialization.
(mount_info::from_registry): Remove v1 table import.
(mount_info::read_v1_mounts): Eliminate.
(mount_info::import_v1_mounts): Ditto.
* shared_info.h (mount_info): Ditto for both of above.
* sys/mount.h (MOUNT_DEVFS): New enum.
(MOUNT_PROC): Ditto.

winsup/cygwin/external.cc

@@ -161,9 +161,8 @@ cygwin_internal (cygwin_getinfo_types t, ...)
 	return (DWORD) cygwin_version_strings;
 
       case CW_READ_V1_MOUNT_TABLES:
-	/* Upgrade old v1 registry mounts to new location. */
-	mount_table->import_v1_mounts ();
-	return 0;
+	set_errno (ENOSYS);
+	return 1;
 
       case CW_USER_DATA:
 	return (DWORD) &__cygwin_user_data;