Setting Symbol.species should change the return value of constructor #239

            var emptyFunc=function() {};
            var p = Promise.resolve(1);
            p.constructor = {};
            var pt1=p.then(emptyFunc);
            console.log('pt1='+pt1);

            var t = function(e) {
                e(emptyFunc, emptyFunc);
            };
            p.constructor[Symbol.species] = t;
            var pt2=p.then(emptyFunc);
            console.log('pt2='+pt2);
            console.log(pt2 instanceof t);