[llvm] [LLVM] Add zstd compressed frame magic to LLVM magic (PR #222773)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> I think we should only support object file formats that LLVM itself supports. For your offload use case, you can use a function different from `identify_magic(Compressed)`

I'm not sure I see the value in this. There are already loads of magic identifies that don't correspond to an `ObectFile::create`.

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