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

[Fangrui Song via llvm-commits]

MaskRay 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)`

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