Object.is and signed zero comparison

[Alexey Lebedev]

Object.is -- like using the === operator programmatically, but also true for NaN vs NaN and +0 vs -0

It's false for +0 vs. -0:

Object.is(+0, -0); // => false
Object.is(-0, -0); // => true

From MDN:

Two values are the same if one of the following holds:
[...]
both numbers and

• both +0
• both -0
• both NaN

[Nicolás Bevacqua]

Care to PR?

[Nicolás Bevacqua]

Fixed by #5