support for object.assign() inheritance

[kimus]

Super class:

var Animal = function() {
}

Animal.prototype.sleep = function() { ... }

Inherit from Super:

var Dog = function() {
}

Dog.prototype = Object.create(Animal.prototype);
Dog.prototype.constructor = Dog;

This is not supported, converted has is:

Object.assign(Dog.prototype, {
    talk: function() { ... }
});

Workaround that generates proper code:

Dog.prototype = {
    talk: function() { ... }
};