[clang] [llvm] [LLVM] Infer compression format from zlib and zstd headers (PR #222773)

[James Henderson via cfe-commits]

https://github.com/jh7370 commented:

Sorry for the delay - I've had a bit of a deluge of PRs recently, so have been struggling to keep on top of them. Basically this looks like what I had in mind. One remaining minor comment though.

https://github.com/llvm/llvm-project/pull/222773