Reorder when we assign the property value to NULL which is identical to
a3a3964497
Just for the declared property case instead of dynamic.
Closes GH-12114
* Add behavioural tests for incdec operators
* Add support to ++/-- for objects castable to _IS_NUMBER
* Add str_increment() function
* Add str_decrement() function
RFC: https://wiki.php.net/rfc/saner-inc-dec-operators
Co-authored-by: Ilija Tovilo <ilija.tovilo@me.com>
Co-authored-by: Arnaud Le Blanc <arnaud.lb@gmail.com>