User: Deprecate confusingly-named isLoggedIn() method

Bug: T270450
Change-Id: I0b8f66d15162fb29abbb922fb79c22e21b3b54dd

RELEASE-NOTES-1.36

@@ -345,6 +345,8 @@ because of Phabricator reports.
 * The User class, which was marked as @newable in 1.35, is no longer newable,
   meaning that it is no longer safe to manually call the constructor via
   `new User`. Instead, use the UserFactory service.
+* The confusingly-named User->isLoggedIn() method has been deprecated in favour
+  of the method it wraps, User->isRegistered().
 * Use of the `preprocessor=Preprocessor_DOM` option in parser test files has
   been deprecated.  Preprocessor_DOM was removed in 1.35.
 * ParserOptions::setTidy() has been deprecated.  It has had no effect since

includes/user/User.php

@@ -2974,7 +2974,9 @@ class User implements IDBAccessObject, UserIdentity {
 	}
 
 	/**
-	 * Get whether the user is logged in
+	 * Get whether the user is registered.
+	 *
+	 * @deprecated since 1.36; use isRegistered() directly
 	 * @return bool
 	 */
 	public function isLoggedIn() {