tcg/optimize: Do not skip default processing of dup_vec

If we do not opimize away dup_vec, we must mark its output as changed.

Fixes: 170ba88f45
Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Tested-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20180805233258.31892-1-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

tcg/optimize.c

@@ -1094,9 +1094,9 @@ void tcg_optimize(TCGContext *s)
                 tmp = arg_info(op->args[1])->val;
                 tmp = dup_const(TCGOP_VECE(op), tmp);
                 tcg_opt_gen_movi(s, op, op->args[0], tmp);
-                continue;
+                break;
             }
-            break;
+            goto do_default;
 
         CASE_OP_32_64(not):
         CASE_OP_32_64(neg):