[llvm] [ADT] Add DenseSet(llvm::from_t, Range) (PR #131832)

[Jakub Kuderski via llvm-commits]

kuhar wrote:

Thanks for the context. Do we have any alternatives for llvm containers? For example, could we follow what we do with `llvm::to_vector` and a generic helper function like `to_set<DenseSet>(bar)` / `to_set<DenseSet<Foo>>(bar)`?

https://github.com/llvm/llvm-project/pull/131832