[R6RS] Final expression in programs

[William D Clinger]

In my opinion, the best solution is to add an exit
procedure to the (r6rs scripts) library (whatever
it will be called in 5.92) that exits the program
(i.e. throws to the end of the program).  With no
arguments, the exit procedure should (not "must")
tell the OS that the program exited normally.
With one argument, the exit procedure should (not
"must") translate the argument in some unspecified
but presumably OS-appropriate way into the kind of
exit value that the OS will understand.

Will