Advantages of setting the "constructor" Property in the "prototype"

In JavaScript Prototype inheritance, what is the goal of adding prototype.constructor property. Let me explain with an example.

var Super = function() {
    this.superProperty = 'Super Property'
}
var Sub = function() {
    this.subProperty = 'Sub Property'
}

Sub.prototype = new Super();
Sub.prototype.constructor = Sub; // advantages of the statement

var inst = new Sub();

The following lines return always true in all case, when adding Sub.prototype.constructor = Sub or not.

console.log(inst instanceof Sub)   // true
console.log(inst instanceof Super) // true

I guess, it may be useful when getting new instances but when and/or how?

Thanks in advance.