Linux 4.15 rc5

Ok, so it's not Sunday yet, but tomorrow is Christmas Eve, and while
I've been in the US for over two decades, we still celebrate Christmas
the only _right_ way - with Christmas Eve being the big day, and
Christmas Day being just for recovery.

So I'm doing the rc5 release a day early, in order to not have to do
it during the actual Christmas festivities at our house.

And it's not like I expect to see a lot of patches or pull requests
tomorrow anyway, so I guess it doesn't really much matter when I do
the rc release, the end result would look very similar even if I had
done it on my normal Sunday schedule.

This (shortened) week ended up being fairly normal for rc5, with the
exception of the ongoing merging of the x86 low-level prep for kernel
page table isolation that continues and is noticeable. In fact, about
a third of the rc5 patch is x86 updates due to that. It all looks like
very good cleanups, though, and it's been through about two hundred
iterations by now (no, seriously, Thomas has been keeping track of his
iterative updates of the PTI series, and it apparently hit 196 in the
last two months).

Outside of that, things look fairly normal: mostly drivers and some
networking updates (bpf fixes and selftests are notable). Some xfs
fixes also stand out.

The appended shortlog gives an overview of the details,