private modifier for constructor

[dipacs]

Sometimes the private modifier on the constructor can be useful, especially if you want to implement some kind of singletons.

[kitsonk]

What would the emit look like for this? Sounds like it would clearly break/not be compatible with ES6 classes. What would be the proposed behaviour on new? If you were creating a singleton, why not just an object literal using the ES6 notation?

const mySingleton = {
  foo() { console.log() }
};

[DanielRosenwasser]

Duplicate of #2341.