[lld] [lld][ELF] Extend profile guided function ordering to ELF binaries (PR #117514)

[Ellis Hoag via llvm-commits]

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

LGTM! Thanks for ensuring this works for both targets! I tested that `MachO/bp-section-orderer-stress.s` produced the same order before and after that change, so it gives me some confidence that this won't regress anything. And I'm curious what size results you get for ELF, so please publish that when it is available.

https://github.com/llvm/llvm-project/pull/117514