build: Enable control flow guard on Windows

build: Enable control flow guard on Windows

This enables the 'Control Flow Guard' security feature, which
prevents memory corruption vulnerabilites by placing a restriction
on where application can execute from.

The change is applied to both VulkanRT and it's NSIS installer.

WARN:  This change requires re-patching and rebuillding NSIS with
attached patch.
WARN#2: This change requires Visual Studion 2015 or vs140 toolset to
take effect.

Control Flow Guard documentation:
https://msdn.microsoft.com/en-us/library/windows/desktop/mt637065(v=vs.85).aspx

Change-Id: I7683c0570087d994961c79fb64419509f83536a8