[llvm] [llvm][DebugInfo] formatv - Tests (PR #191980)

[Konrad Kleine via llvm-commits]

kwk wrote:

> Viewed independently from other PRs LGTM, but please wait if David has something to add

Alright. Thank you!

@s-barannikov just to be clear, I've not used a tool so each of the other PRs target `main`. They are not dependent on one another. Therefore the PRs can be viewed independently and merged independently. I've done a hard reset to `origin/main` locally and manually cherry-picked one of my per-file commits. Then I've reset again repeated it for the next commit and so forth. This resulted in 28 PRs in total. But they should be small in size and should hopefully speed up the review process.

https://github.com/llvm/llvm-project/pull/191980