bug#32731: 26.1.50; Ibuffer filter by mode: Handle >1 mode names

[Eli Zaretskii]

> From: Tino Calancha <tino.calancha@gmail.com>
> Date: Tue, 18 Sep 2018 04:53:56 +0900 (JST)
> cc: Tino Calancha <tino.calancha@gmail.com>, npostavs@gmail.com, 
>     32731@debbugs.gnu.org
> 
> >> Noam Postavsky <npostavs@gmail.com> writes:
> >>
> >>> Shouldn't this patch be going into master anyway (since it's adding a
> >>> new feature)?
> >> I think is pretty tiny and safe new feature.
> >
> > "Tiny and safe feature" doesn't necessarily cut it.  It has to be
> > something important.  Is it?
> It's not important; just for convenience.
> It doesn't bring anything new: you can get the same result just typing
> more keys.

Then I think we had better put it on master.

Thanks.