You could also receate the additional signals on the 8052 using software and maybe interupts.

Depending on what you are doing you may not need flow control at all.

Example PC sends a short message, The 8052 responds. Since the PC has a large buffer, and the message to the 8052 can be handled. There is not flow control needed. Flow control will be needed if the PC can send dat to the 8052 faster than it can be accepted or processed.