Add Math Extensions proposal to Stage 1 TC39 0716

[clavecoder]

Implementation is based on the polyfill submitted along with the proposal.

[edit] The related TC39 meeting notes have dropped:
https://github.com/rwaldron/tc39-notes/blob/master/es7/2016-07/jul-26.md#9iie-math-extensions

This is my first PR, so it will need some work. I modeled the changes off of Number.epsilon and Math.umulh. The tests pass. Below are a list of open items. Please inform any other ways I can improve my submissions.

Open items:

1. The README doesn't specify the version, of course.
2. The spec also creates two well-known intrinsic objects %Math_max%, %Math_min%. Can they, should they be modeled in some way? They are used in the specification of Math.clamp.
3. For the following files the computation of the constants was exported rather than the constant itself, following the pattern of Math.umulh. Should the identifier be exported? If so, how?
   • library/fn/math/deg-per-rad.js
   • library/fn/math/rad-per-deg.js
4. In the following, I'm invoking Math.max, Math.min, and Math.PI directly. Should I create variables instead, as seems to be the pattern?
   • library/modules/es7.math.clamp.js
   • library/modules/es7.math.deg-per-rad.js
   • library/modules/es7.math.rad-per-deg.js
   • library/modules/es7.math.radians.js
   • modules/es7.math.clamp.js
   • modules/es7.math.deg-per-rad.js
   • modules/es7.math.rad-per-deg.js
5. In the following, I haven't been able to import constants and functions defined by core.js, what is the way to do so?
   • library/modules/es7.math.degrees.js
   • library/modules/es7.math.fscale.js (including a call to scale)
   • library/modules/es7.math.scale.js
   • library/modules/es7.math.radians.js
   • modules/es7.math.degrees.js
   • modules/es7.math.fscale.js (including a call to scale)
   • modules/es7.math.scale.js
   • modules/es7.math.radians.js
6. Looks like I need to add some <CR>s at the end of some files.

[zloirock]

Thanks. I'll completely review it little later, at this moment some comments.

[zloirock]

Can you exclude browser bundles from this PR? It will be updated only at release.

[clavecoder]

That's everything under client/, right?

[zloirock]

Yep.

[clavecoder]

Done (previously)

[clavecoder]

Changes per requested. Couple new git commands learned too, 😃.

[zloirock]

Use https://rwaldron.github.io/proposal-math-extensions/ link.

[clavecoder]

Done.

[clavecoder]

@zloirock, I've updated for your second round of comments. It should be in order now. I used Math.PI for the fscale/fround test.

[zloirock]

cc @rwaldron what do you think about it? Mainly interesting your position about Math.fscale. It's missed in the spec, but in opened questions and in your implementation.

[clavecoder]

@zloirock , @rwaldron, Any updates on this Math-Extensions pr?

[zloirock]

@clavecoder I wanted at first to have a feedback from proposal's champion, but if it's missing... I'll merge it and publish a new release when I'll have some free time.

[clavecoder]

Great, I'll try to move on to adding a PR for the more important #225 on Saturday.