Add babel-minify-standalone

[Daniel15]

Similar to #6029, except for babel-minify. Moves babili-standalone from the repo (https://github.com/babel/babel-standalone) into this repo, and renames it to babel-minify-standalone.

[boopathi]

Is this an important/required change for including babel-minify-standalone ?

If so, then all the plugin and preset tests will run on babel7 instead of babel6, and almost everyone using this minifier would be using it with babel6.

[Daniel15]

I had some build errors with 6.x. I can try again and see if I can get it working. I think it was because the latest babel-standalone versions reference babel-core 7.x.

Is there a branch of babel-minify for Babel 7.x builds?

[vigneshshanmugam]

There is a open PR for babel 7 upgrade here #487

[vigneshshanmugam]

the file extension is missing l for html.

[Daniel15]

It's consistent with babel-standalone: https://github.com/babel/babel/blob/7.0/packages/babel-standalone/examples/example.htm

Should I change both?

[vigneshshanmugam]

Interesting, I thought this extension was dead long before. Its totally up to you :)

[Daniel15]

Thanks for the info @vigneshshanmugam! I might wait for #487 to be merged first.

[boopathi]

@Daniel15 #487 is merged now.

[Daniel15]

Thanks! I won't have time to look into this for a while though. Would you like to try rebasing it and see if these changes still work?

[boopathi]

Sure. I'll rebase it.

[boopathi]

I hit a wall -

The registerBabelStandaloneTask is moved from babel-standalone repo to here - https://github.com/babel/babel/blob/master/scripts/gulp-tasks.js