[llvm] [ADT] SCC iterator for general graph (PR #84268)

[Jakub Kuderski via llvm-commits]

kuhar wrote:

@zyd2001 Thanks for the context. The way I see it is that it's a nice improvement but it comes at the expense of future maintenance. If there are not uses in the code base, it is likely to suffer from 'bit rot'.

> However, I think the problem is that the current documentation and interface of SCC Iterator is misleading. It says "Enumerate the SCCs of a directed graph in reverse topological order of the SCC DAG" and the interface just accepts a graph.

What do you think about improving the documentation and/or adding an assertion instead?

https://github.com/llvm/llvm-project/pull/84268