target/riscv: trans_rvv: Avoid assert for RV32 and e64

target/riscv: trans_rvv: Avoid assert for RV32 and e64

When running a 32-bit guest, with a e64 vmv.v.x and vl_eq_vlmax set to
true the `tcg_debug_assert(vece <= MO_32)` will be triggered inside
tcg_gen_gvec_dup_i32().

This patch checks that condition and instead uses tcg_gen_gvec_dup_i64()
is required.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1028
Suggested-by: Robert Bu <robert.bu@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220608234701.369536-1-alistair.francis@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>