[lld] [lld] Implement getOutputCharacteristics for non-section code thunks. (PR #70721)

[Martin Storsjö via llvm-commits]

https://github.com/mstorsjo approved this pull request.

LGTM, thanks!

The case of reexporting the thunk of an imported function is kinda contrieved though - I presume that only would happen in a contrieved setup when manually requesting it to be exported? The autoexporter doesn't export them, right?

https://github.com/llvm/llvm-project/pull/70721