new (class Foo extends class { } {
	constructor() {
		let x = 1;
		(async () => {
			console.log("before super", x);  // (1) Sync phase
			await 1;
			console.log("after super", x);   // (2) Async phase
		})();
		super();
		x = 2;
	}
})();

before super 1
after super 2

Uncaught ReferenceError: Must call super constructor in derived class before accessing 'this' or returning from derived constructor