Closure::call() makes a temporary copy of original closure function, modifies its
scope, resets ZEND_ACC_CLOSURE flag and call it through zend_call_function().
As result the same function may be called with and without
ZEND_ACC_CLOSURE flag, that confuses JIT and may lead to memory leak or
even worse memory errors.
The patch allocates "fake" closure object and keep ZEND_ACC_CLOSURE flag
to always behave in the same way.