Implement myInstanceof(obj, Ctor)
Write myInstanceof(obj, Ctor) that replicates the instanceof operator by walking obj's prototype chain, checking for Ctor.prototype.
class Animal {}
class Dog extends Animal {}
myInstanceof(new Dog(), Animal); // true, through the chain
myInstanceof(new Dog(), Array); // false
myInstanceof(5, Number); // false, primitives have no prototype chain