bug#18556: 24.4.50; update-file-autoloads never ends

[Paul Eggert <eggert@cs.ucla.edu>]

I could not reproduce the problem with Emacs trunk bzr 117958 built on 
Fedora 20 with GCC 4.9.1, in either 32- or 64-bit builds, and in either 
en_US.UTF-8 or fr_FR.iso885915@euro locales.  Here's the behavior I 
observed:

$ ls -l /tmp/d/balance.el
-rw-r--r--. 1 eggert eggert 110567 Sep 26 09:38 /tmp/d/balance.el
$ time src/emacs -Q --batch '--eval=(update-file-autoloads 
"/tmp/d/balance.el" nil "/tmp/d/my_autoloads.el")'
Generating autoloads for /tmp/d/balance.el...
Wrote /tmp/d/my_autoloads.el
Generating autoloads for /tmp/d/balance.el...done

real    0m0.041s
user    0m0.033s
sys    0m0.007s
$ ls -l /tmp/d/my_autoloads.el
-rw-r--r--. 1 eggert eggert 260 Sep 26 09:56 /tmp/d/my_autoloads.el
$ cat /tmp/d/my_autoloads.el
;;; my_autoloads.el --- automatically extracted autoloads
;;
;;; Code:

\f
(provide 'my_autoloads)
;; Local Variables:
;; version-control: never
;; no-byte-compile: t
;; no-update-autoloads: t
;; coding: utf-8
;; End:
;;; my_autoloads.el ends here