[clang] [InstallAPI][Tests] Update tests to be resilient to reversion iteration config (PR #89270)

[Cyndy Ishida via cfe-commits]

cyndyishida wrote:

> How hard would it be to make the output here have a consistent order? I mean, emitting diagnostics in a consistent order isn't nearly as important as emitting consistent binaries, but it's still nice to have if we can get it easily.

I don't think it's too hard in general, but a little more effort to get it done in a performant fashion for the passing InstallAPI case. Something I'd want to profile before committing to.

https://github.com/llvm/llvm-project/pull/89270