[php-src] Issue #12531: When returning a property by reference that was previously deleted, it is recreated.

Issue: https://github.com/php/php-src/issues/12531 Author: alexeyp0708 ### Description The following code: ```php <?php class A{ public $prop='hello'; } $a=new A; unset($a->prop); echo $a->prop;// Warning: Undefined property: A::$prop var_dump(isset($a->prop),property_exists($a,'prop'));//false,true $var= & $a->prop; echo $a->prop;// empty (no errors) var_dump(isset($a->prop),property_exists($a,'prop'));//false,true ``` Resulted in this output: ``` Warning: Undefined property: A::$prop in /home/user/scripts/code.php on line 12 bool(false) bool(true) bool(false) bool(true) ``` But I expected this output instead: ``` Warning: Undefined property: A::$prop in /home/user/scripts/code.php on line 12 bool(false) bool(true) Warning: Undefined property: A::$prop in /home/user/scripts/code.php on line 12 bool(false) bool(true) ``` The same is true when returning a property by reference in a method ```php <?php class A{ public $prop='hello'; public function getProp(){ return $this->prop; } public function & getRefProp(){ return $this->prop; } } $a=new A; unset($a->prop); echo $a->getProp(); // Warning: Undefined property: A::$prop echo $a->getRefProp(); // No error echo $a->getProp(); // No error ``` Resulted in this output: ``` Warning: Undefined property: A::$prop in /home/user/scripts/code.php on line 5 ``` But I expected this output instead: ``` Warning: Undefined property: A::$prop in /home/user/scripts/code.php on line 5 Warning: Undefined property: A::$prop in /home/user/scripts/code.php on line 5 Warning: Undefined property: A::$prop in /home/user/scripts/code.php on line 5 ``` ### PHP Version PHP 8.3.0RC5, PHP 7.4.33 ### Operating System _No response_