Its From the soundtrack Glory By James Horner.. it's looks like Carmina Burana but it Isn't.
So Check out the soundtrack from Glory..!
"All those moment's will be lost, Like tears in the Rain" Roy Batty

It IS opera! It's a piece on Carl Orff's Carmina Burana. It's also used in the Exorcist. On that soundtrack it's named apocalyptica, but that's not it's real name. Problem is, in the Crying Freeman-trailer, it's an alternate take on the original. It made it almost impossible for me to track it down, but actually, the differences aren't that big. So check the Exorcist soundtrack or just buy/download Carl Orff's Carmina Burana and you'll have what you searched for!