This is on top of #9297

I was curious if (ab)using the compute::unary kernel would perform better on slightly complex functions.

I implemented the Haversine function, which calculates the distance between two geographic coordinates.
I then benchmarked an implementation that I tried to simplify and optimise with unary kernels, vs one that I'd have to write if I couldn't use the unary kernels for things like:

• arithmetics with scalars
• functions that would otherwise require generating intermediate arrays (e.g. sin(x) * cos(x) would be multiply(sin(x), cos(x)))

The function that uses unary kernels for the above, is slightly faster.

I ran this on an M1 CPU, with the below options

cargo bench --bench trigonometry_kernels
cargo bench --bench trigonometry_kernels --features simd
RUSTFLAGS="-C target-cpu=native" cargo bench --bench trigonometry_kernels
RUSTFLAGS="-C target-cpu=native" cargo bench --bench trigonometry_kernels --features simd

haversine_no_unary 512  time:   [14.074 us 14.140 us 14.216 us]

haversine_unary 512     time:   [11.191 us 11.308 us 11.436 us]
haversine_no_unary_nulls 512                                                                             
                        time:   [15.902 us 15.985 us 16.083 us]

haversine_unary_nulls 512                                                                             
                        time:   [12.486 us 12.552 us 12.625 us]

The biggest benefit is from setting the RUSTFLAGS, the non-null benches go 3-10% faster.