TypeScript property override proposal

demo.js

var __extends = this.__extends || function (d, b) {
    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
    function __() { this.constructor = d; }
    __.prototype = b.prototype;
    d.prototype = new __();
};
var __findPropertyDescriptor = this.__findPropertyDescriptor || function(o, p) {
    while (o !== null) {
      var r = Object.getOwnPropertyDescriptor(o, p);
      if (r) return r;
      o = Object.getPrototypeOf(object);
    }
    return undefined;
};
var Base = (function () {
    function Base() {
    }
    Object.defineProperty(Base.prototype, "foo", {
        get: function () {
            return "Foo!";
        },
        enumerable: true,
        configurable: true
    });
    return Base;
})();

var Derived = (function (_super) {
    __extends(Derived, _super);
    function Derived() {
        _super.apply(this, arguments);
    }
    var _super_get_foo = __findPropertyDescriptor(_super.prototype, "foo").get;
    Object.defineProperty(Derived.prototype, "foo", {
        get: function () {
            return "Derived " + _super_get_foo.call(this);
        },
        enumerable: true,
        configurable: true
    });
    return Derived;
})(Base);

demo.ts

class Base {
	get foo() { return "Foo!"; }
}

class Derived extends Base {
	get foo() {
		return "Derived " + super.foo;
	}
}