all: update to Unicode 11

all: update to Unicode 11

This does *not* update the vendored tables.
A commit updating these tables should follow soon,

Mostly generated running UNICODE_VERSION=11.0.0 in x/text.

Manually updated next.txt file.

Updates golang/go#27945.

Change-Id: I939a01e235aeca898ee9afc99a531e7ad8444e12
Reviewed-on: https://go-review.googlesource.com/c/go/+/154420
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>