Support ES7 async/await proposal

I’m talking about https://github.com/lukehoban/ecmascript-asyncawait. It’s an accepted proposal for ES7.

Because https://github.com/6to5/6to5 can already compile these, it would be nice to have support for it behind a flag.

I wouldn’t file issues for other ES7 features yet but this one is a game changer. It spoiled me as a C# developer a few years ago and I can’t wait to start using it again.

(Yes I understand this can be done with yield. Bear with me!)

[platinumazure]

@MarkHerhold You need to set ecmaVersion to 8 under parserOptions in configuration, or do the equivalent in CLI.

Configuration (JSON):

{
    "parserOptions": {
        "ecmaVersion": 8 // or 2017
    },
    "rules": {}
    }
}

Via CLI:

eslint --parser-options="ecmaVersion:8"

[ljharb]

@MarkHerhold set your ecmaVersion to 2017.