Fix not emit removeListener when eventName type is 'symbol'.

```js
const EventEmitter = require('events');
const myEmitter = new EventEmitter();
const sym = Symbol('symbol');
const fn = () => { };
myEmitter.on(sym, fn);

myEmitter.on('removeListener', (...args) => {
  console.log('removeListener');
  console.log(args, args[0] === sym, args[1] === fn);
});

myEmitter.removeAllListeners()
```

When the listener's eventName type is 'symbol' and removeListener is called with no parameters, removeListener should be emitted.