tcg/optimize: Handle add/sub with carry opcodes

Propagate known carry when possible, and simplify the opcodes
to not require carry-in when known.  The result will be cleaned
up further by the subsequent liveness analysis pass.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
1 file changed