Sort and hashing algorithms

https://www.deepmind.com/blog/alphadev-discovers-faster-sorting-algorithms

Sort: https://reviews.llvm.org/D118029
Hash: https://github.com/abseil/abseil-cpp/commit/74eee2aff683cc7dcd2dbaa69b2c654596d8024e

The sorting one is in libc++ but we would like to work with any stdlib, and rely less on stdlib.