this is not as good as phpstan/phpstan-src#769 (e.g. array_key_first()/array_key_last() aren't covered by this, nor is array_rand()) but it does eliminate the most infuriating cases where this usually crops up.
comparing enums with equality operators is unreliable because there is no guarantee that the enum objects won't be somehow duplicated, through serialization, cloning or ext-parallel dumb object copying. This means that two equal enum objects may not be thw same object.
