China’s world-beating gambling hub is getting a taste of Hollywood glamor as its newest casino resort makes its debut on Tuesday with a glitzy grand opening that masks turmoil behind the scenes. Pop diva Mariah Carey, film stars Leonardo DiCaprio and Robert De Niro and director Martin Scorsese are among the celebrities enlisted to help launch Melco Crown Entertainment Ltd.’s $3.2 billion Studio City project in Macau.