Fix #75958 Return void instead of true

UPGRADING

@@ -314,6 +314,9 @@ PHP 8.0 UPGRADE NOTES
   . SplHeap::compare($a, $b) now specifies a method signature. Inheriting
     classes implementing this method will now have to use a compatible
     method signature.
+  . SplDoublyLinkedList::push() now returns void instead of true
+  . SplDoublyLinkedList::unshift() now returns void instead of true
+  . SplQueue::enqueue() now returns void instead of true
 
 - Standard:
   . assert() will no longer evaluate string arguments, instead they will be

ext/spl/spl_dllist.c

@@ -567,8 +567,6 @@ SPL_METHOD(SplDoublyLinkedList, push)
 
 	intern = Z_SPLDLLIST_P(ZEND_THIS);
 	spl_ptr_llist_push(intern->llist, value);
-
-	RETURN_TRUE;
 }
 /* }}} */
 
@@ -585,8 +583,6 @@ SPL_METHOD(SplDoublyLinkedList, unshift)
 
 	intern = Z_SPLDLLIST_P(ZEND_THIS);
 	spl_ptr_llist_unshift(intern->llist, value);
-
-	RETURN_TRUE;
 }
 /* }}} */
 

ext/spl/spl_dllist.stub.php

@@ -17,13 +17,13 @@ class SplDoublyLinkedList implements Iterator, Countable, ArrayAccess, Serializa
 
     /**
      * @param mixed $value
-     * @return bool
+     * @return void
      */
     public function push($value) {}
 
     /**
      * @param mixed $value
-     * @return bool
+     * @return void
      */
     public function unshift($value) {}
 
@@ -105,7 +105,7 @@ class SplQueue extends SplDoublyLinkedList
 {
     /**
      * @param mixed $value
-     * @return bool
+     * @return void
      */
     public function enqueue($value) {}