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

[Nikita Popov via llvm-commits]

nikic wrote:

@kuhar I think the way history played out there is that we added to_vector for this use case, but then still ended up adding the ArrayRef overload to SmallVector later because the ergonomics of having the ctor are just better.

I think that if there are no technical issues with it, having a ctor accepting a range is a good idea.

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