[llvm] [ObjectYAML][NFC] Make BBAddrMap encoder diagnostics format-neutral (PR #202524)

[James Henderson via llvm-commits]

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

Technically not an NFC, given the typo fix. I'd drop "NFC" from the PR description/commit comment.

Otherwise, LGTM.

https://github.com/llvm/llvm-project/pull/202524