https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87626

[Jakub Jelinek]

On Sun, Jan 06, 2019 at 06:25:35PM +0100, Martin Liška wrote:
> The patch causes failures in libffi:
> https://github.com/libffi/libffi/issues/463
> 
> Can you please take a look?

Perhaps PR88521?  A patch has been posted for that and even approved:
https://gcc.gnu.org/ml/gcc-patches/2018-12/msg01682.html
but not actually committed yet.

	Jakub