bug#27571: Crashing when printing a lisp object.

[Keith David Bershatsky]

The trick of `ulimit -S -s unlimited` does not work with Emacs 26.0.50 master 
branch (built 07/25/2017) on OSX 10.6.8.  This may be traceable back to a 
commit on 11/19/2017 described in the related thread of bug #27779:  
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=27779  And, there may be several 
commits subsequent to 11/19/2017 that prevent the trick from working on OSX 
10.6.8.

(require 'cl-lib)

(defun make-deep-object (depth)
    (let ((obj 1))
      (while (> (cl-decf depth) 0)
        (setq obj (vector (list obj))))
      obj))

(let* ((print-circle t)
       (max-lisp-eval-depth most-positive-fixnum)
       (max-specpdl-size most-positive-fixnum)
       (deep-object (make-deep-object 6000))
       (string (prin1-to-string deep-object)))
  (when string
    (message "Success! (%d)" (length string))))