Should we allow SuperProperty directly inside static block?

```js
class B {
  static foo = "b";
}
class C extends B {
  static foo = "c";
  static {
    this.bar = super.foo;
  }
}
```
Currently the spec allows `SuperProperty` in static block. However I want to know if it is intentional. If so it will be good to add an example to README.