Function vdup_lane_s16 

pub fn vdup_lane_s16(a: int16x4_t, const N: i32) -> int16x4_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.

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