fixup: use listenerCount instead of _events

Author: apapirovski

lib/domain.js

@@ -402,8 +402,7 @@ EventEmitter.prototype.emit = function emit(...args) {
 
   const type = args[0];
   const doError = type === 'error' &&
-                  this._events !== undefined &&
-                  this._events.error !== undefined;
+                  this.listenerCount(type) > 0;
 
   if (doError || domain === null || domain === undefined || this === process) {
     return Reflect.apply(eventEmit, this, args);