Function vsetq_lane_u8 

pub fn vsetq_lane_u8(a: u8, b: uint8x16_t, const LANE: i32) -> uint8x16_t

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

Insert vector element from another vector element Arm’s documentation