bug#30193: The deadliest file in Emacs history

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson
>       <jidanni@jidanni.org>
> Date: Sun, 21 Jan 2018 17:54:25 +0800
> 
> Fatal error 11: Segmentation fault
> Backtrace:
> emacs[0x50a5fe]...
> /lib/x86_64-linux-gnu/libpthread.so.0(+0x11fb0)[0x7fc827b75fb0]
> /usr/lib/x86_64-linux-gnu/libotf.so.0(OTF_drive_gpos_with_log+0x2a)[0x7fc828527a2a]
> /usr/lib/x86_64-linux-gnu/libm17n-flt.so.0(+0x24f2)[0x7fc8280e04f2]...

The crash seems to be inside the libotf/libm17n-flt library; CC'ing
Handa-san who may have comments on this.

Meanwhile, please make sure you have the latest versions of these
libraries installed.

FWIW, it doesn't crash here on MS-Windows, where these libraries are
not used by Emacs.

Thanks.