This patch adds support for C3.5.3 Add/subtract (with carry):
instructions ADC, ADCS, SBC, SBCS.
Signed-off-by: NClaudio Fontana <claudio.fontana@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>