target/riscv: fix rsub gvec tcg_assert_listed_vecop assertion

gvec should provide vecop_list to avoid:
"tcg_tcg_assert_listed_vecop: code should not be reached bug" assertion.
Signed-off-by: NFrank Chang <frank.chang@sifive.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-Id: <20200710104920.13550-2-frank.chang@sifive.com>
Signed-off-by: NAlistair Francis <alistair.francis@wdc.com>

target/riscv/insn_trans/trans_rvv.inc.c

@@ -958,22 +958,27 @@ static void gen_rsub_vec(unsigned vece, TCGv_vec r, TCGv_vec a, TCGv_vec b)
 static void tcg_gen_gvec_rsubs(unsigned vece, uint32_t dofs, uint32_t aofs,
                                TCGv_i64 c, uint32_t oprsz, uint32_t maxsz)
 {
+    static const TCGOpcode vecop_list[] = { INDEX_op_sub_vec, 0 };
     static const GVecGen2s rsub_op[4] = {
         { .fni8 = gen_vec_rsub8_i64,
           .fniv = gen_rsub_vec,
           .fno = gen_helper_vec_rsubs8,
+          .opt_opc = vecop_list,
           .vece = MO_8 },
         { .fni8 = gen_vec_rsub16_i64,
           .fniv = gen_rsub_vec,
           .fno = gen_helper_vec_rsubs16,
+          .opt_opc = vecop_list,
           .vece = MO_16 },
         { .fni4 = gen_rsub_i32,
           .fniv = gen_rsub_vec,
           .fno = gen_helper_vec_rsubs32,
+          .opt_opc = vecop_list,
           .vece = MO_32 },
         { .fni8 = gen_rsub_i64,
           .fniv = gen_rsub_vec,
           .fno = gen_helper_vec_rsubs64,
+          .opt_opc = vecop_list,
           .prefer_i64 = TCG_TARGET_REG_BITS == 64,
           .vece = MO_64 },
     };