Function vdupq_lane_p8 

pub fn vdupq_lane_p8(a: poly8x8_t, const N: i32) -> poly8x16_t

Available on little-endian and target feature neon and (AArch64 or ARM or ARM64EC) and (AArch64 or ARM64EC) and (AArch64 or ARM64EC or target feature v7) only.

Set all vector lanes to the same value Arm’s documentation