[llvm] [JITlink][AArch32] Move function declaration from unittest to headers (PR #71621)

[Stefan Gränitz via llvm-commits]

weliveindetail wrote:

> If we don't want to expose these functions to the API, then I think I can special case them and just add the visibility attributes on the implementation.

Yes, would be great if that's possible. They should all have visibility("hidden") I think.

https://github.com/llvm/llvm-project/pull/71621