Justice Ruth Bader Ginsburg of the Supreme Court on Thursday expressed regret for her recent remarks about the candidacy of Donald J. Trump, saying they were “ill-advised.” Earlier this week, Justice Ginsburg called Mr. Trump “a faker” who “really has an ego” and said he had been treated too gently by the press. Mr. Trump, she said, “says whatever comes into his head at the moment” and has no consistency in his thinking. She also made critical remarks in interviews with The New York Times and The Associated Press.