[PHP-DEV] ReflectionType for iterable / PHP 8.2

[Benjamin Morel]

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