> > See https://github.com/php/php-src/pull/2136
> On a technical note this is a potentially breaking change for C
> extensions. Since it is a currently a `zend_bool` its value is
> truthy/falsy; you are now applying specific meaning to values.
> Maybe someone else will have more insight into what might be affected
> realistically, but this is one reason this was not implemented this
> way to begin with.
Note that Nikita's proposal (i.e. stick to 7.0 behavior and ignore the
"nullable" bit) is free from this problem yet really fine also as far as BC