windows: add memory-related VirtualX calls and associated constants

Fixes golang/go#20086

Change-Id: Ifdc2561fe6cc125fa45a57bad9750f3f3f055e66
Reviewed-on: https://go-review.googlesource.com/47335
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
4 files changed