what is the solana_frozen_abi crate and what is it used for?
I've seen it here: https://github.com/solana-labs/solana/blob/27eff8408b7223bb3c4ab70523f8a8dca3ca6645/program-runtime/src/compute_budget.rs#L7
It's also once thrown around when compiling programs with an error Getting error while compiling the program
Essentially, the whole idea is to avoid making breaking changes to certain structs. The macro takes all of the types in a struct or enum and hashes them together to create a digest. If anything in the struct differs, the hash should change, signifying a breaking change that should be handled carefully.
You can learn more about it at https://docs.solanalabs.com/implemented-proposals/abi-management
