Function merge_dps_stats 

pub fn merge_dps_stats(
    running_n: &mut u64,
    running_wsum: &mut u64,
    running_m2_bits: &mut u64,
    running_min: &mut u32,
    running_max: &mut u32,
    chunk_n: u32,
    chunk_mean_x10: u32,
    chunk_m2_bits: u64,
    chunk_min: u32,
    chunk_max: u32,
)

Merge chunk DPS stats into the running aggregate via Chan/Golub/LeVeque pairwise merge.