Subject: bug#12471: Avoid some signal-handling races, and simplify.

From: Eli Zaretskii <[email-masked]>
Date: Sun, 23 Sep 2012 05:55:44 +0200

> Date: Sat, 22 Sep 2012 14:55:23 -0700
> From: Paul Eggert <[email-masked]>
> CC: Eli Zaretskii <[email-masked]>, [email-masked], 
>  [email-masked]
> 
> +/* Internal signals.  */
> +#define emacs_raise(sig) kill (getpid (), sig)

Windows will use a different definition.  I'll probably just implement
'emacs_raise' as a function.  I want to keep 'sys_kill' only for
sending "signals" to subprocesses.