[llvm] [Object][ELF] Remove internal linkage from header function templates (NFC) (PR #202969)

[James Henderson via llvm-commits]

https://github.com/jh7370 approved this pull request.

LGTM.

This seems to mostly be a revert of 1db7d2ae226c96e0243309e1688c6e0cfb9236bd by @goldsteinn. They landed that change directly in main without review (as far as I can tell) and with only the comment "Add missing static decl on several helpers", i.e. no explanation as to why in their opinion this was the right thing to do. Had this gone via a PR, I would have probably have asked the question "why?" with a view that the change was incorrect, so I'm happy for this to proceed. However, it may be worth waiting a few days, up to a week, to give @goldsteinn a chance to comment.

https://github.com/llvm/llvm-project/pull/202969