Inconsistent behaviour with node inherits

I have a node class that inherits Event emitter:

```
function MyClass() {
EventEmitter.call(this);
}
util.inherits(MyClass, EventEmitter);
```

This class also has it's prototype object with methods:

```
MyClass.prototype.foo = function() {};
```

When I run my code on node (5.4) everything runs smoothly, but once webpack'ed the MyClass prototype gets squashed and only the EventEmitter methods survive.

Start by reproducing the issue with the MyClass/EventEmitter inheritance snippet under Node 5.4 and after webpack bundling. Compare the resulting MyClass prototype in both environments; done means the custom foo method remains available alongside the inherited EventEmitter methods.

Written by the indexing model from the issue text.