Fill out GPU_Vulkan.cpp with what's mostly a copy of GLES_GPU.cpp

Core/System.cpp

@@ -386,7 +386,10 @@ bool PSP_InitStart(const CoreParameter &coreParam, std::string *error_string) {
 #else
 	INFO_LOG(BOOT, "PPSSPP %s", PPSSPP_GIT_VERSION);
 #endif
+	
+	GraphicsContext *temp = coreParameter.graphicsContext;
 	coreParameter = coreParam;
+	coreParameter.graphicsContext = temp;
 	coreParameter.errorString = "";
 	pspIsIniting = true;