[llvm] [FreeBSD] Mark __stack_chk_guard dso_local except for PPC64 (PR #86665)

[Dimitry Andric via llvm-commits]

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

Yes, this is handy to reduce the amount of diffs we have in FreeBSD. :)

https://github.com/llvm/llvm-project/pull/86665