Babel bug with `this` inside async arrow function - npm i && npm test

.000-README

babel-preset-stage-2 pulls in the newest version of babel-plugin-transform-async-to-generator,
however the async arrow function still has `this` = `undefined`.

If I manually install babel-plugin-transform-async-to-generator and add it to the list of plugins
in .babelrc, everything works as expected.

Steps to reproduce:

$ npm install && npm test

.babelrc

{
  "presets": ["es2015-node4", "stage-2"],
  "plugins": ["transform-es2015-arrow-functions"]
}

package.json

{
  "name": "babel-preset-async-arrow",
  "version": "1.0.0",
  "scripts": {
    "test": "babel-node test.js"
  },
  "engines": {
    "node": "4.2.3"
  },
  "dependencies": {
    "babel-plugin-transform-async-to-generator": "^6.4.6",
    "babel-plugin-transform-es2015-arrow-functions": "^6.3.13",
    "babel-preset-es2015-node4": "^2.0.2",
    "babel-preset-stage-2": "^6.3.13",
    "babel-register": "^6.3.13"
  },
  "devDependencies": {
    "babel-eslint": "^5.0.0-beta6",
    "babel-plugin-transform-runtime": "^6.3.13",
    "babel-preset-es2015": "^6.3.13",
    "babel-runtime": "^6.3.13"
  },
  "private": true
}

test.js

'use strict';

(function() {
  console.log(`It works if next 3 lines are`, this);
  [1,2,3].map(async (foo)=> { console.log(this) });
}).bind({ x: 1 })();

// Output:
//
// It works if next 3 lines are { x: 1 }
// undefined
// undefined
// undefined
//
// Expected output:
// It works if next 3 lines are { x: 1 }
// { x: 1 }
// { x: 1 }
// { x: 1 }
//