Stub Vulkan backend support

A lot of the architecture of the emulator here does not allow for vulkan
to initialize easily since it involves a bit of data to be exchanged
between SDL and Vulkan. This commit just adds the foundational linkage
and library code for vulkan support.

src/core/PICA/gpu.cpp

@@ -12,6 +12,9 @@
 #ifdef PANDA3DS_ENABLE_OPENGL
 #include "renderer_gl/renderer_gl.hpp"
 #endif
+#ifdef PANDA3DS_ENABLE_VULKAN
+#include "renderer_vk/renderer_vk.hpp"
+#endif
 
 using namespace Floats;
 
@@ -38,11 +41,12 @@ GPU::GPU(Memory& mem, EmulatorConfig& config) : mem(mem), config(config) {
 			break;
 		}
 #endif
-
+#ifdef PANDA3DS_ENABLE_VULKAN
 		case RendererType::Vulkan: {
-			Helpers::panic("Vulkan is not supported yet, please pick another renderer");
+			renderer.reset(new RendererVK(*this, regs));
+			break;
 		}
-
+#endif
 		default: {
 			Helpers::panic("Rendering backend not supported: %s", Renderer::typeToString(config.rendererType));
 			break;

src/core/renderer_vk/renderer_vk.cpp

@@ -0,0 +1,19 @@
+#include "renderer_vk/renderer_vk.hpp"
+
+RendererVK::RendererVK(GPU& gpu, const std::array<u32, regNum>& internalRegs) : Renderer(gpu, internalRegs) {}
+
+RendererVK::~RendererVK() {}
+
+void RendererVK::reset() {}
+
+void RendererVK::display() {}
+
+void RendererVK::initGraphicsContext() { static vk::DynamicLoader dl; }
+
+void RendererVK::clearBuffer(u32 startAddress, u32 endAddress, u32 value, u32 control) {}
+
+void RendererVK::displayTransfer(u32 inputAddr, u32 outputAddr, u32 inputSize, u32 outputSize, u32 flags) {}
+
+void RendererVK::drawVertices(PICA::PrimType primType, std::span<const PICA::Vertex> vertices) {}
+
+void RendererVK::screenshot(const std::string& name) {}

src/core/renderer_vk/vulkan_api.cpp

@@ -0,0 +1,3 @@
+#include "renderer_vk/vulkan_api.hpp"
+
+VULKAN_HPP_DEFAULT_DISPATCH_LOADER_DYNAMIC_STORAGE;