tcg/i386: Honor carry_live in tcg_out_movi

Do not clobber flags if they're live.  Required in order
to perform register allocation on add/sub carry opcodes.

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

tcg/i386/tcg-target.c.inc

@@ -1092,7 +1092,7 @@ static void tcg_out_movi_int(TCGContext *s, TCGType type,
 {
     tcg_target_long diff;
 
-    if (arg == 0) {
+    if (arg == 0 && !s->carry_live) {
         tgen_arithr(s, ARITH_XOR, ret, ret);
         return;
     }