renderer_vulkan: Implement S8_UINT stencil format

It should be noted that on Windows, only nvidia gpus support this format natively as of this commit.

src/video_core/renderer_vulkan/maxwell_to_vk.cpp

@@ -208,6 +208,9 @@ struct FormatTuple {
     {VK_FORMAT_D32_SFLOAT, Attachable}, // D32_FLOAT
     {VK_FORMAT_D16_UNORM, Attachable},  // D16_UNORM
 
+    // Stencil formats
+    {VK_FORMAT_S8_UINT, Attachable}, // S8_UINT
+
     // DepthStencil formats
     {VK_FORMAT_D24_UNORM_S8_UINT, Attachable},  // D24_UNORM_S8_UINT
     {VK_FORMAT_D24_UNORM_S8_UINT, Attachable},  // S8_UINT_D24_UNORM (emulated)

src/video_core/renderer_vulkan/vk_texture_cache.cpp

@@ -102,6 +102,7 @@ constexpr VkBorderColor ConvertBorderColor(const std::array<float, 4>& color) {
             usage |= VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
             break;
         case VideoCore::Surface::SurfaceType::Depth:
+        case VideoCore::Surface::SurfaceType::Stencil:
         case VideoCore::Surface::SurfaceType::DepthStencil:
             usage |= VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
             break;
@@ -173,6 +174,8 @@ constexpr VkBorderColor ConvertBorderColor(const std::array<float, 4>& color) {
         return VK_IMAGE_ASPECT_COLOR_BIT;
     case VideoCore::Surface::SurfaceType::Depth:
         return VK_IMAGE_ASPECT_DEPTH_BIT;
+    case VideoCore::Surface::SurfaceType::Stencil:
+        return VK_IMAGE_ASPECT_STENCIL_BIT;
     case VideoCore::Surface::SurfaceType::DepthStencil:
         return VK_IMAGE_ASPECT_DEPTH_BIT | VK_IMAGE_ASPECT_STENCIL_BIT;
     default:
@@ -195,6 +198,8 @@ constexpr VkBorderColor ConvertBorderColor(const std::array<float, 4>& color) {
     case PixelFormat::D16_UNORM:
     case PixelFormat::D32_FLOAT:
         return VK_IMAGE_ASPECT_DEPTH_BIT;
+    case PixelFormat::S8_UINT:
+        return VK_IMAGE_ASPECT_STENCIL_BIT;
     default:
         return VK_IMAGE_ASPECT_COLOR_BIT;
     }

src/video_core/vulkan_common/vulkan_device.cpp

@@ -21,6 +21,13 @@
 namespace Vulkan {
 namespace {
 namespace Alternatives {
+constexpr std::array STENCIL8_UINT{
+    VK_FORMAT_D16_UNORM_S8_UINT,
+    VK_FORMAT_D24_UNORM_S8_UINT,
+    VK_FORMAT_D32_SFLOAT_S8_UINT,
+    VK_FORMAT_UNDEFINED,
+};
+
 constexpr std::array DEPTH24_UNORM_STENCIL8_UINT{
     VK_FORMAT_D32_SFLOAT_S8_UINT,
     VK_FORMAT_D16_UNORM_S8_UINT,
@@ -74,6 +81,8 @@ void SetNext(void**& next, T& data) {
 
 constexpr const VkFormat* GetFormatAlternatives(VkFormat format) {
     switch (format) {
+    case VK_FORMAT_S8_UINT:
+        return Alternatives::STENCIL8_UINT.data();
     case VK_FORMAT_D24_UNORM_S8_UINT:
         return Alternatives::DEPTH24_UNORM_STENCIL8_UINT.data();
     case VK_FORMAT_D16_UNORM_S8_UINT:
@@ -145,6 +154,7 @@ std::unordered_map<VkFormat, VkFormatProperties> GetFormatProperties(vk::Physica
         VK_FORMAT_R4G4B4A4_UNORM_PACK16,
         VK_FORMAT_D32_SFLOAT,
         VK_FORMAT_D16_UNORM,
+        VK_FORMAT_S8_UINT,
         VK_FORMAT_D16_UNORM_S8_UINT,
         VK_FORMAT_D24_UNORM_S8_UINT,
         VK_FORMAT_D32_SFLOAT_S8_UINT,