Switch away from things that are removed in C++17

Switch away from things that are removed in C++17

Summary:
That currently includes `std::binary_function`, `std::unary_function`, and `std::random_shuffle`.
`std::{unary|binary}_function<T{, T2}, Ret>` changes to `std::function<Ret(T{, T2})>`.
`std::random_shuffle` has no immediate equivalent, but `std::shuffle` while passing a specific RNG achieves the same effect.

Reviewed By: yfeldblum

Differential Revision: D3506405

fbshipit-source-id: cdefc698a841eca762174eddd8ce636e2d8d26ef