bug#32932: 27.0.50; render bugs on macOS Mojave

[Eli Zaretskii]

> Date: Thu, 8 Nov 2018 23:21:13 +0000
> From: Alan Third <alan@idiocy.org>
> Cc: Eli Zaretskii <eliz@gnu.org>, 32932@debbugs.gnu.org,
>       boris@d12frosted.io
> 
> I’ve got another patch for you to try first, though. This one
> requires the previous one (i.e. you should be able to just apply it
> without the removing anything).

If this is eventually installed, please add comments to explain why we
disregard the garbaged flag for NS.

Thanks.