“I’m so glad I saw you in time. This is the bike lane. Are you okay?” This will embarrass them without leaving them yelling at you. And it will avoid your being rude in the event that the pedestrian’s crime was not premeditated.
If us bike riders think of ourselves as faster pedestrians, rather than as slower cars, this seems like reasonable advice. Do you really need to zip past and yell at everyone who happens to be in front of you?