fix error tip-61: Binding objects to functions

[GeoffZhu]

fix error tip-61: Binding objects to functions

jstips was awesome! But when i read tip-61, There are two noticeable error in the code

• arrow function were already bound this.
• Function.prototype.bind just bind target this for the fun, not call it.

[zenopopovici]

Yep you're right. Thanks @GeoffZhu !