graphics: unify buffer bindings and depth target handling

src/graphics/shader/recompiler/ShaderIR.h

@@ -705,9 +705,15 @@ struct BindingLayout {
 	uint32_t                       descriptor_set       = 0;
 	uint32_t                       push_constant_offset = 0;
 	uint32_t                       push_constant_size   = 0;
+	uint32_t                       buffer_offset_dword  = 0;
+	uint32_t                       buffer_offset_count  = 0;
 	std::vector<uint32_t>          user_data_registers;
 	std::vector<DescriptorBinding> descriptors;
 
+	[[nodiscard]] uint32_t ShaderDataDwords() const {
+		return buffer_offset_dword + (buffer_offset_count + 3u) / 4u;
+	}
+
 	bool operator==(const BindingLayout& other) const = default;
 };