bug#15103: 24.3.50; Wrong byte compiler warning

[Stefan Monnier]

> I have a file test.el:
> (condition-case err
>     (ignore)
>   (file-error (ignore))
>   (error (message "%s" (error-message-string err))))
[...]
> In toplevel form:
> test.el:1:1:Warning: Unused lexical argument `err'
> Wrote /home/albinus/tmp/test.elc

If you set byte-compile--use-old-handlers to nil, the above spurious
warning should now be fixed.


        Stefan