Function compute_order 

pub fn compute_order(
    dims: &[usize],
    strides_list: &[&[isize]],
    dest_index: Option<usize>,
) -> Vec<usize>

Compute the optimal iteration order for dimensions.

This implementation follows Julia’s _mapreduce_order! algorithm:

1. Compute index_order for each array’s strides
2. Compute importance scores using bit-packing with output weighted 2x
3. Sort dimensions by importance (descending)