ReferenceError / Instance prototype not found

The following sample yields on `js` and `eval` but not on `hl` or `neko` (Haxe 4.3.1 on https://try.haxe.org/#02bf26bF):

```haxe
class Test {
static var sub = new Sub();
static function main() {}
}

@:keep class Sub extends Test {
public function new() {}
}
```

JavaScript yields:
```
ReferenceError: can't access lexical declaration 'Test' before initialization
````

Eval yields:
```
[WARNING] Test.hx:1: lines 1-5

1 | class Test {
- | [...]
5 | }
|
| (WStaticInitOrder) Warning : maybe loop in static generation of Test

[ERROR] Test.hx:1: lines 1-5

1 | class Test {
- | [...]
5 | }
|
| [0] Instance prototype not found: Test
```