Use packed_simd_2

[Gelbpunkt]

This updates packed_simd to 0.3.4, which is sadly only available on the packed_simd_2 crate (more on that at rust-lang/packed_simd#298). It fixes compilation with the simd-accel feature on recent nightly toolchains.

[hsivonen]

Thanks. What's the purpose of using package = "packed_simd_2" instead of changing the dependency name to packed_simd_2?

[Gelbpunkt]

It allows past use statements for packed_simd to work even though the name changed to packed_simd_2. I assume they recommended it in case they get ownership of packed_simd on crates.io again. This way it is only required to change one line instead of all imports in the code files.

If you would like to use packed_simd_2 directly nonetheless, I'll happily update the files, just let me know!

[hsivonen]

OK. Thanks.