Replace the __riscv_vid_v_i32m2 and __riscv_vid_v_i64m2 with __riscv…_vid_v_u32m2 and __riscv_vid_v_u64m2 for riscv64-unknown-linux-gnu-gcc compiling.

Replace the __riscv_vid_v_i32m2 and __riscv_vid_v_i64m2 with __riscv…_vid_v_u32m2 and __riscv_vid_v_u64m2 for riscv64-unknown-linux-gnu-gcc compiling. #641