[llvm] [docs][passes] Update documentation of Analysis and Transform Passes (PR #80835)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

LGTM. I've been meaning to write a script that parses the `opt -print-passes` output and compares it with the sections here to automatically identify gaps (as it existed before in some hacky form), and maybe even run it in CI. It hasn't been high on my priority list however.

https://github.com/llvm/llvm-project/pull/80835