A new parameter, $langcode has been added to menu_tree_all_data() so that menu data can be requested for a specific language.

Before:

$tree = menu_tree_all_data($menu_name, NULL, NULL);

After:

$tree = menu_tree_all_data($menu_name, NULL, NULL, $langcode);
Introduced in branch: 
1.17.x
Introduced in version: 
1.17.5
Impacts: 
Module developers
Related Github Issues: 
https://github.com/backdrop/backdrop-issues/issues/4857