target/riscv: rvv: Add CHECK arg to GEN_OPFVF_WIDEN_TRANS

Signed-off-by: Anton Blanchard <antonb@tenstorrent.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Max Chou <max.chou@sifive.com>
Signed-off-by: Max Chou <max.chou@sifive.com>
Message-ID: <20250408103938.3623486-3-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Cc: qemu-stable@nongnu.org