Interestingly the spec script for the movie "The Package" was called, "Eggplant Emoji" when Netflix had purchased it, it was renamed to 'the package' and Netflix continues to advertise it solely as the eggplant emoji.
However, of course once mousing over, it gives its actual title, so likely this is just a kind of easter egg. But with that said, I remember it vividly as the only movie I've ever seen that didn't have a title with it, besides the eggplant emoji.
As far as specific regulations go, no amount of googling has let me find a naming regulation, advised or forced otherwise that explicitly prohibits naming of films in any sort of meaningful way, besides changing its potential rating. (Namely going from say, PG, R, X, or XXX).
As such, It appears that no, there are no limits on using odd symbols or emojis. Besides the fact a person would probably forget the title of the film, or hard to find.
CFC Film regulations
Motion Picture Act Regulations