Taskstats is a netlink-based interface for sending per-task and
per-process statistics from the kernel to userspace.

For more information, please see:
https://www.kernel.org/doc/Documentation/accounting/taskstats.txt.

Fixes golang/go#21616.

Change-Id: I7d4b8035aa8e993074d61911d9a8c3a3e61c9b2e
Reviewed-on: https://go-review.googlesource.com/59050
Run-TryBot: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>