Fix zend_lazy_object_get_properties for object with prop ht, when init fails

[arnaud-lb]

zend_lazy_object_get_properties() is used by zend_std_get_properties_ex() to fetch the properties of lazy objects. It initializes the object and returns its properties.

When initialization fails we return an empty array instead because most callers do not check for NULL. We rely on the exception thrown during initialization. We also assign that empty array to zend_object.properties for the same reasons.

We asserted that zend_object.properties was either NULL or &zend_empty_array, but there are other cases in which a uninitialized lazy object may have a properties ht.

Here I remove the assertion, and return the existing properties ht if there is one. Otherwise I return zend_new_array(0) instead of &zend_emtpy_array as not all callers expect an immutable array (e.g. FE_FETCH does not).

Fixes GH-15823.

[iluuu1994]

LGTM!