loader: Create defaults for which platforms WSI is supported on.
loader: Create defaults for which platforms WSI is supported on.

Windows: VK_USE_PLATFORM_WIN32_KHR
Linux:   VK_USE_PLATFORM_XCB_KHR

sashinde/VulkanTools,elongbug/Vulkan-LoaderAndValidationLayers,sashinde/VulkanTools,critsec/Vulkan-LoaderAndValidationLayers,Radamanthe/VulkanSamples,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,critsec/Vulkan-LoaderAndValidationLayers,critsec/Vulkan-LoaderAndValidationLayers,Radamanthe/VulkanSamples,elongbug/Vulkan-LoaderAndValidationLayers,sashinde/VulkanTools,critsec/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,Radamanthe/VulkanSamples,elongbug/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,sashinde/VulkanTools,Radamanthe/VulkanSamples,Radamanthe/VulkanSamples,Radamanthe/VulkanSamples