h. Opcache may make classes and op_arrays immutable. Such classes are marked

by ZEND_ACC_IMMUTABLE flag, they are not going to be copied from opcache

Few related data structures were changed to allow addressing mutable data

structures from immutable ones. This access is implemented through

ZEND_MAP_PTR... abstraction macros and, basically, uses additional level of

indirection. op_array->run_time_cache, op_array->static_variables_ptr,

class_entry->static_members_table and class_entry->iterator_funcs_ptr now

It's also not allowed to change op_array->reserved[] handles of immutable

op_arrays. Instead, now you have to reserve op_array handle using

zend_get_op_array_extension_handle() during MINIT and access its value