CZ does. I had a 9 hour layover in CAN and was put up at the Pullman hotel at the airport (landside.) The hotel was quite nice. Other airlines that I know do this are EK, TK and perhaps OZ.

However, if the hotel choices offered by CA for transit pax are anything like those used for missed connections, I would skip it and book my own hotel. I missed a connection at PEK and CA put us up at the Golden Phoenix hotel (or something like that) and it was dreadful. Best avoided.