SBCL can be stopped at any time by calling
optionally returning a specified numeric value to the calling process.
See notes in Threading about the interaction between this
feature and sessions.
— Function: sb-ext:quit &key recklessly-p unix-status
Terminate the current Lisp.
*exit-hooks* and pending unwind-protect
cleanup forms are run unless
recklessly-p is true. On UNIX-like
unix-status is used as the status code.