Implement PortableHasher from the portable-hash crate #36
Description
The portable-hash crate would enable us to provide a rapidhash::v3::RapidHasherV3 to portably hash arbitrary rust types across all platform, crate, and compiler versions. The std type behaviour may vary between rust compiler versions, and so aren't suitable for this.
If this would be useful for you, please like the issue and I'll spend more time on it!