Issue #1987418 by joelpittet, drupalninja99, rakhimandhania, Manuel Garcia, scor, shanethehat, Cottser, LinL, LewisNyman, minneapolisdan: User.module - Convert theme_ functions to Twig.

Issue #2124957 by Wim Leers, catch: Replace 'content' cache tag with 'rendered' and use it sparingly.

Issue #2203407 by nod_, sun: Replace #attached library array values with provider-namespaced strings.

Issue #2081205 by mrsinguyen: Remove Unused local variable $rid from /core/modules/user/lib/Drupal/user/Form/UserPermissionsForm.php.

Issue #2074509 by tim.plunkett, falcon03, mgifford, Xano: Fixed Add missing #title property to ensure form accessibility.

Issue #2057869 by dawehner, jibran: Provide an alias for 'plugin.manager.entity' called 'entity.manager'.

Issue #1938888 by tim.plunkett, ayelet_Cr, amateescu: Convert user_admin_permissions() to a new-style Form object.