message: refactor(sample): remove unnecessary variable declaration
  It did not really improve readability, and I could not see the benefit of keeping it.
diff: @@ -54,14 +54,19 @@ export function sample<T>(notifier: Observable<any>): MonoTypeOperatorFunction<T
  lastValue = value;
  })
  );
  - const emit = () => {
  + notifier.subscribe(
  + new OperatorSubscriber(
  + subscriber,
  + () => {
  if (hasValue) {
  hasValue = false;
  const value = lastValue!;
  lastValue = null;
  subscriber.next(value);
  }
  - };
  - notifier.subscribe(new OperatorSubscriber(subscriber, emit, noop));
  + },
  + noop
  + )
  + );
  });
  }
  