Compiler emits code that crashes when extending 'null'

[DanielRosenwasser]

function f() {
    class C extends null {
        constructor() { return Object.create(null); }
    }
    var c = new C();
    return !(c instanceof Object)
        && Function.prototype.isPrototypeOf(C)
        && Object.getPrototypeOf(C.prototype) === null;
}

console.log(f());

Expected: true
Actual:

    __.prototype = b.prototype;                    
                    ^                              
TypeError: Cannot read property 'prototype' of null