Linux 4.18 rc8

So as already mentioned a couple of times in some of the relevant
threads, this last week wasn't entirely painless, and 4.18 ended up
being one of those releases that gets an extra week of rc testing
before release.

The original impetus for this was the continued VM worries - although
it looks like we finally root-caused all the issues and got it all in
shape on Wednesday. Still, that is somewhat late, and merits another
rc for final testing.

That said, if it had been _only_ that silly VM issue that turned out
to not be so annoying as it could have been, I might have reconsidered
and done a final release anyway, but we had some last-minute
networking noise too, and there's actually a pending (old) VFS issue
too. So while I may prefer to keep our regular release cadence, but
this time around we are just going to see that extra week.

I realize that this may mess with people who had planned for the merge
window to start tomorrow - particularly the Europeans where August is
often peak vacation time. Never fear, you can send me your merge
window pull request next week as planned, and I'll just sit on it for
the extra week. So go off on your planned vacations.

Anyway, appended is the shortlog for the changes during the last week
- and despite the extra week, it's not really horrible. Over a quarter
of the patch is tooling updates, with some testing and tooling updates
for perf, turbostat and bpf.

On the actual kernel side, most of the (small) changes were to
drivers, with network drivers leading the way. There's also some core
networking changes, along with some minor arch updates.

And we've got the VM fixes. and misc noise elsewhere. See below for
the shortlog, or delve into the git repo for the nitty-gritty details.