[clang] [llvm] [CMake] Version Darwin dylib identities (PR #189004)

[Steven Wu via llvm-commits]

cachemeifyoucan wrote:

> Ah, please do not squash and merge. These commits are intentionally factored the way that they are; the first two are preparatory cleanup and only the last one introduces behavior change. If a revert is needed, best that only the last commit is reverted. I'd like to retain all the commit messages, please.

We only have squash and merge in LLVM. History is linear with no merge commit. If you want to split it, please recreate with individual PRs.

https://github.com/llvm/llvm-project/pull/189004