target/mips/mxu: Add D32ADD instruction The instruction adds/subtracts two 32-bit values in XRb and XRc. Placing results in XRa and XRd and updates carry bits for each path in the MXU control register. Signed-off-by: Siarhei Volkau <lis8215@gmail.com> Message-Id: <20230608104222.1520143-16-lis8215@gmail.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>