class field initializers are broken in subclasses

```js
class A {}
class B extends A {
  b = 2
  constructor() { super() }
}
print(1)
new B() // throws, but shouldn't
print(2)
```

Output:
```
1
Uncaught exception: ReferenceError: Uninitialized this binding
```

Expected:
```
1
2
```

e.g. https://npmjs.com/@noble/hashes uses that