In #18297 we merged a hardware-accelerated Base.crc32c hash function, with the intention of using it to validate .ji files etcetera, but we never got around to using it. This issue is a reminder that we should:

• Use the checksum where appropriate, probably for validating .ji files (use crc32c checksum to validate .ji cache files #21240).
• Export and document the crc32c function so that users can benefit from it as well (see e.g. the mailing list and the CRC.jl package — currently, CRC.jl is used by Elly, Gallium, and ZipFile, and probably all of them could benefit from a hardware-accelerated built-in crc32c). (clean up and export crc32c function #22274)