Add SIMD support for the length kernel

[HaoYang670]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
We could calculate offset[1 ..] - offset[.. offset.len()] by simd.

Describe the solution you'd like

1. simd support for length kernel
2. some benchmark results.

[jhorstmann]

The compiler should be able to autovectorize the existing length kernel, at least it does in a smaller example: https://rust.godbolt.org/z/7sjrrfxqf

If this does not happen in the actual arrow kernel then we probably need to investigate whether MutableBuffer::from_trusted_len_iter somehow prevents that optimization.