Add Harrah’s Entertainment Inc. to the list of Las Vegas gaming companies facing class-action lawsuits filed by securities lawyers. Harrah’s was sued last month in U.S. District Court in Delaware by two bondholders who claim a recent debt-exchange deal engineered by Harrah’s benefited some big corporate bondholders while placing other classes of bondholders in jeopardy, should Harrah’s default on its debt or file for bankruptcy protection.