kernel: avoid signed overflow UB on MSVC

src/common/CMakeLists.txt

@@ -91,6 +91,7 @@ add_library(common STATIC
     multi_level_page_table.h
     nvidia_flags.cpp
     nvidia_flags.h
+    overflow.h
     page_table.cpp
     page_table.h
     param_package.cpp

src/common/overflow.h

@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <type_traits>
+#include "bit_cast.h"
+
+namespace Common {
+
+template <typename T>
+    requires(std::is_integral_v<T> && std::is_signed_v<T>)
+inline T WrappingAdd(T lhs, T rhs) {
+    using U = std::make_unsigned_t<T>;
+
+    U lhs_u = BitCast<U>(lhs);
+    U rhs_u = BitCast<U>(rhs);
+
+    return BitCast<T>(lhs_u + rhs_u);
+}
+
+} // namespace Common