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

[David Blaikie via llvm-commits]

dwblaikie wrote:

OK, so the use of from_t is for consistency, if nothing else - I'm OK with that? Having range based ctors would be nice, and having them work the same way as standard containers will work seems fine/good to me.

Other people feel strongly otherwise?

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