SBCL can be stopped at any time by calling sb-ext:quit,
optionally returning a specified numeric value to the calling process.
See notes in Threading about the interaction between this
feature and sessions.
Terminate the current Lisp. Things are cleaned up (with
unwind-protect and so forth) unless recklessly-p is non-NIL. On
UNIX-like systems, unix-status is used as the status code.