WSI-ICD: Created per-platform structs for platform-specific info.
WSI-ICD: Created per-platform structs for platform-specific info.

Per Khronos Bugzilla Bug 15077, on Windows and Linux, VkSurfaceKHR is treated
as a pointer to platform-specific structs that contain the platform-specific
connection and surface/window info.  The Vulkan loader vkCreate*SurfaceKHR()
functions will fill in the struct.  ICDs and layers will cast VkSurfaceKHR to a
pointer to the appropriate VkIcdSurface* struct.

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