ReflectionType for iterable / PHP 8.2

Hi internals,

It just came to my attention that there is a change of behaviour between
PHP 8.1 and 8.2 in the way iterable is decomposed, or not, into
Traversable|array when reflected:

function foo(): iterable {}
function bar(): stdClass|iterable {}

echo (new ReflectionFunction('foo'))->getReturnType(), PHP_EOL;
echo (new ReflectionFunction('bar'))->getReturnType(), PHP_EOL;

Output on PHP 8.1:

iterable
stdClass|iterable

Output on PHP 8.2:

iterable
stdClass|Traversable|array

Is this expected behaviour? Or should I file a bug? I'm particularly
surprised that it behaves this way on PHP 8.2 only in the presence of union
types.

Thank you,
Benjamin

That's a intentional behaviour change and related to this accepted PHP
8.2 RFC: https://wiki.php.net/rfc/iterator_xyz_accept_array

Smile,
Juliette