6 files declare their use of SortArray in Drupal 8

common.inc in core/includes/common.inc

Common functions that many Drupal modules will need to reference.

ConfigDependencyManager.php in core/lib/Drupal/Core/Config/Entity/ConfigDependencyManager.php

HelpTopicPluginController.php in core/modules/help_topics/src/Controller/HelpTopicPluginController.php

MediaLibraryWidget.php in core/modules/media_library/src/Plugin/Field/FieldWidget/MediaLibraryWidget.php

SortArrayTest.php in core/tests/Drupal/Tests/Component/Utility/SortArrayTest.php

WidgetBase.php in core/lib/Drupal/Core/Field/WidgetBase.php