tcg: Save/restore vecop_list around minmax fallback

Forgetting this asserts when tcg_gen_cmp_vec is called from
within tcg_gen_cmpsel_vec.

Fixes: 72b4c792c7a
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/tcg-op-vec.c

@@ -657,7 +657,9 @@ static void do_minmax(unsigned vece, TCGv_vec r, TCGv_vec a,
                       TCGv_vec b, TCGOpcode opc, TCGCond cond)
 {
     if (!do_op3(vece, r, a, b, opc)) {
+        const TCGOpcode *hold_list = tcg_swap_vecop_list(NULL);
         tcg_gen_cmpsel_vec(cond, vece, r, a, b, a, b);
+        tcg_swap_vecop_list(hold_list);
     }
 }