Reproduce a strange bug in the current (6.8.2) version of Babylon

To observe the error in action, just run:

npm install
npm run build

Or, alternatively:

./build.sh

Which is exactly the same thing. It will attempt to babelify and webpack the index.js into dist/bundle.js, but will run into an error as described in the source file. The exact output from the webpack command should match that in build_result.