Add Arrow Function lexical arguments example

[empyrical]

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[PandaWhisperer]

I recently found out about this behavior the hard way, which caused me considerable emotional distress. This PR would have helped me avoid that.

Please merge.

[empyrical]

Not sure if my PR has any issues or not (maybe my example is awkward?) In the meantime though you could use the spread operator on arrow funcs to get that behaviour, like so:

fs.readFile('package.json', (...args) => { console.log(args) })

[PandaWhisperer]

Thanks @empyrical. Brendan Eich told me the same thing after I forwarded him my tweet. Had a discussion with him on Twitter about this the other day. Good guy.

I hope your PR gets merged soon. I really like this repo and I've used it as a reference to learn ES6. Until I ran headfirst into this issue without any warning and felt like there definitely should have been one. Could have saved me a couple hours of debugging and wondering whether I've gone insane or my computer did.

I'm just so used to using console.log(arguments) to debug my call parameters anytime something doesn't work as expected, and suddenly, that was giving me anything from an exception to undefined to completely different arguments. Very annoying to say the least. Like walking full speed into a glass door.