Prior to the fork of Drupal, locale_language_list() was removed.

Drupal.org issue: https://www.drupal.org/node/1387608
Changelog: https://www.drupal.org/node/1414264

Although it was described as though these two functions were redundant, locale_language_list() had the helpful ability to return an array suitable for use in a select list. Backdrop 1.2.0 restores this ability by adding a second parameter to the language_list() function.

Prior to Backdrop 1.2.0:

<?php
$languages
= array();
foreach (
language_list() as $langcode => $language) {
 
$languages[$langcode] = $language->name;
}
?>

Backdrop 1.2.0 and later:

<?php
$languages
= language_list(FALSE, TRUE);
?>
Introduced in branch: 
1.2.x
Introduced in version: 
1.2.0
Impacts: 
Module developers
Related Github Issues: 
https://github.com/backdrop/backdrop-issues/issues/604