gvt-next-2018-09-04

- guest context shadow optimization for restore inhibit one (Yan)
- cmd parser optimization (Yan)
- W=1 warning fixes (Zhenyu)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

# Conflicts:
#	drivers/gpu/drm/i915/gvt/reg.h
From: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904030154.GG20737@zhen-hp.sh.intel.com