[RFC] Block all async signals used by gdb when initializing Guile

[Doug Evans]

On Sat, Aug 29, 2015 at 1:16 PM, Eli Zaretskii <eliz@gnu.org> wrote:
>> Date: Sat, 29 Aug 2015 12:20:24 -0700
>> From: Doug Evans <xdje42@gmail.com>
>> Cc: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>, guile-devel <guile-devel@gnu.org>
>>
>> > What about platforms that don't have sigprocmask, but do have SIGINT?
>> > Don't we want to block SIGINT on those platforms?
>>
>> Do they have threads
>
> They might.  (The only way I've succeeded to have a working Guile on
> Windows was to disable threads, but I hope that bug will be fixed one
> day.)
>
>> and how does one block SIGINT on those platforms?
>
> With a call to 'signal', I guess.

I'm guessing that won't work here, we'll need something else.
The issue is we need the threads that guile starts
to have these signals blocked. Then after guile init
returns we unblock the signals.