Bug Report

Current Behavior
When working with async/await and setting IE11 as a target, it does not always include es6.promise.

Input Code

• https://github.com/rbnlffl/mehrsprachig/blob/master/src/mehrsprachig.js

async getLocale() {
    const req = await fetch(this.sources[this.language]);
    const res = await req.json();

    this.locales[this.language] = res;
}

[/Users/robin/Sites/mehrsprachig/src/mehrsprachig.js] Added following polyfills:
  regenerator-runtime { "android":"4.4.3", "chrome":"69", "edge":"17", "firefox":"62", "ie":"11", "ios":"11.3", "opera":"56", "safari":"11.1" }
  web.dom.iterable { "android":"4.4.3", "chrome":"69", "edge":"17", "firefox":"62", "ie":"11", "ios":"11.3", "opera":"56", "safari":"11.1" }
  es6.array.iterator { "android":"4.4.3", "ie":"11" }
  es6.symbol { "android":"4.4.3", "edge":"17", "ie":"11" }
  es7.symbol.async-iterator { "android":"4.4.3", "edge":"17", "ie":"11", "ios":"11.3", "safari":"11.1" }
  es6.regexp.split { "android":"4.4.3", "edge":"17", "ie":"11" }
  es6.regexp.replace { "android":"4.4.3", "edge":"17", "ie":"11" }
  es6.string.includes { "android":"4.4.3", "ie":"11" }
  es7.array.includes { "android":"4.4.3", "ie":"11" }

Expected behavior/code
I expect a polyfill for IE11 for Promises to be included.

Babel Configuration (babel.config.js)

module.exports = {
    sourceMaps: true,
    presets: [
        ['@babel/preset-env', {
            targets: {
                ie: 11,
                browsers: 'last 2 versions'
            },
            useBuiltIns: 'usage',
            debug: true
        }]
    ],
    ignore: [ 'node_modules' ]
};

Environment

• Babel version(s): 7.2.2
• Node/npm version: 10.14.2/6.4.1
• OS: macOS 10.14.2
• Monorepo: no
• How you are using Babel: rollup-plugin-babel

Additional context/Screenshots
I can fix the issue for now by importing whatwg-fetch and promise-polyfill/src/polyfill manually. However, this is not really elegant, as I'm working with a polyfilling package, anyway, and this always includes these polyfills, even when not transforming anything with babel.

Another thing to mention: fetch does not get polyfilled, either. I've read somewhere that you guys think about including it in the future—is this true? If yes, is there any planned eta?