Windows on ARM64 Build

[hmartinez82]

Add ARM64 configuration and #ifdefs

Note:

• Visual Studio requires the C++ ARM64 build tools (latest) component installed
• The ref_vk project is disabled in the ARM64 Configuration since there is no Vulkan SDK support for Windows ARM64, hopefully just yet.
• Binaries are suffixed with A64
• The device needs the freely available OpenCL™ and OpenGL® Compatibility Pack provided by Microsoft itself in the Microsoft Store installed