Extend standard library with ES6 methods

[sbstp]

There's a couple of methods from the ES6 draft that I believe can be implemented without modifying the VM. This issue is a list of them. I'd like to try and tackle some of them. Most of the algorithms are described in the draft. MDN also has examples and polyfills that could be useful while trying to implement some of these functions. I've intentionally left out the methods that cannot be implemented at the moment.

Object

• Object.assign
• Object.is
• Object.setPrototypeOf (__proto__ does not seem to be mutable)

String

• String.fromCodePoint
• String.prototype.codePointAt
• String.prototype.normalize (unicode normalization)
• String.prototype.repeat
• String.prototype.startsWith
• String.prototype.endsWith
• String.prototype.includes

Array

• Array.from
• Array.of
• Array.prototype.copyWithin
• Array.prototype.find
• Array.prototype.findIndex
• Array.prototype.fill
• Array.prototype.keys
• Array.prototype.values
• Array.prototype.entries

Number

• Number.isFinite
• Number.isInteger
• Number.isSafeInteger (might need discussion)
• Number.isNaN
• Number.EPSILON
• Number.MIN_SAFE_INTEGER (might need discussion)
• Number.MAX_SAFE_INTEGER (might need discussion)

Math

• Math.clz32
• Math.imul
• Math.sign
• Math.log10
• Math.log2
• Math.log1p
• Math.expm1
• Math.cosh
• Math.sinh
• Math.tanh
• Math.acosh
• Math.asinh
• Math.atanh
• Math.trunc
• Math.fround
• Math.cbrt
• Math.hypot

[maximecb]

I approve of your proposal. It's a good idea.