Zend: Add tests for offsets and containers (#12723)

Add various tests showcasing the behavioural variations of different offset types used on various container types in all possible operatio

Zend: Add tests for offsets and containers (#12723)

Add various tests showcasing the behavioural variations of different offset types used on various container types in all possible operations:
- Read
- Write
- Read Write
- Appending
- Unsetting
- Existence checks with isset()/empty/null coalesce operator
- Behaviour of nesting dimensions (e.g. $container[$offset1][$offset2])

Add a test to ensure compile time and runtime behaviour is identical for offsets.

Add an internal class that overloads the dimension object handlers to zend_test

show more ...