refactor: remove EventEmitter from facade (#14837)

As of right now each module has its own copy of the EventEmitter
contributing to bloat.

modules/@angular/core/src/core.ts

@@ -29,7 +29,7 @@ export {TRANSLATIONS, TRANSLATIONS_FORMAT, LOCALE_ID, MissingTranslationStrategy
 export {ApplicationModule} from './application_module';
 export {wtfCreateScope, wtfLeave, wtfStartTimeRange, wtfEndTimeRange, WtfScopeFn} from './profile/profile';
 export {Type} from './type';
-export {EventEmitter} from './facade/async';
+export {EventEmitter} from './event_emitter';
 export {ErrorHandler} from './error_handler';
 export * from './core_private_export';
 export {Sanitizer, SecurityContext} from './security';
@@ -59,4 +59,4 @@ export type AnimationStyles = any;
 /**
  * @deprecated from v4
  */
-export type AnimationKeyframe = any;
+export type AnimationKeyframe = any;