Make a Comint process NAME in BUFFER, running PROGRAM.
If BUFFER is nil, it defaults to NAME surrounded by `*'s.
If there is a running process in BUFFER, it is not restarted.
PROGRAM should be one of the following:
- a string, denoting an executable program to create via
- a cons pair of the form (HOST . SERVICE), denoting a TCP
connection to be opened via `open-network-stream'
- nil, denoting a newly-allocated pty.
Optional fourth arg STARTFILE is the name of a file, whose
contents are sent to the process as its initial input.
If PROGRAM is a string, any more args are arguments to PROGRAM.
Return the (possibly newly created) process buffer. (fn NAME BUFFER PROGRAM &optional STARTFILE &rest SWITCHES)