bug#29183: 27.0.50; SIGSEGV on C-g on Windows

[Eli Zaretskii]

> From: John Mastro <john.b.mastro@gmail.com>
> Date: Wed, 8 Nov 2017 10:35:06 -0800
> Cc: 29183@debbugs.gnu.org
> 
> Ah, thanks. After preprocessing, that line becomes:
> 
> static struct thread_state __attribute__ ((aligned (8))) main_thread;

That's what it should have become...

> >> $ gcc --version
> >> gcc.exe (Rev1, Built by MSYS2 project) 7.2.0
> >
> > Should be okay, I think.  Does the problem go away if you remove
> > GCALIGNED from that line in thread.c and rebuild?
> 
> Yep, the SIGSEGV is gone if I remove GCALIGNED from that line.

Hmm... so it sounds like our assumption that this attribute should be
a no-op in this case is incorrect, or maybe it's a bug in GCC 7.2?
Paul?