Add ZEND_ACC_NOT_SERIALIZABLE flag

This prevents serialization and unserialization of a class and its
children in a way that does not depend on the zend_class_serialize_deny
and zend

Add ZEND_ACC_NOT_SERIALIZABLE flag

This prevents serialization and unserialization of a class and its
children in a way that does not depend on the zend_class_serialize_deny
and zend_class_unserialize_deny handlers that will be going away
in PHP 9 together with the Serializable interface.

In stubs, `@not-serializable` can be used to set this flag.

This patch only uses the new flag for a handful of Zend classes,
converting the remainder is left for later.

Closes GH-7249.
Fixes bug #81111.

show more ...