isPrototypeOf & constructor & prototype

if (o1.isPrototypeOf(o2) || o2.isPrototypeOf(o1))
    return false;
if (o1.constructor !== o2.constructor)
    return false;
if (o1.prototype !== o2.prototype)
    return false;

@reference_1_mozilla
@reference_2_mozilla
@reference_3_mozilla