[php-src] PR #22978: Check object_init_ex() in ReflectionMethod::createFromMethodName()

Pull Request: https://github.com/php/php-src/pull/22978 Author: iliaal instantiate_reflection_method() ignores the result of object_init_ex(). On an uninstantiable subclass that call throws, sets the return value to NULL and reports FAILURE, and the helper then runs Z_REFLECTION_P() over the NULL zend_object, offsetting backwards out of the allocation. ```php class C { public function a() {} } abstract class R extends ReflectionMethod {} R::createFromMethodName('C::a'); // SIGSEGV in reflection_prop_name(), php_reflection.c:71 ``` Segfaults on 8.4, 8.5 and master; 8.3 carries the same code. ReflectionClass::newInstance(), newInstanceArgs() and newInstanceWithoutConstructor() already test the result the same way. Found while reviewing #22968, which touches the same helper but does not cause this.