[llvm] [KnownBits] Add KnownBits::makeConstantRange to determine the known bits from a pair of unsigned lo/hi bound values (PR #107080)

[Nikita Popov via llvm-commits]

nikic wrote:

Why do we need this if we have `ConstantRange::toKnownBits()`?

https://github.com/llvm/llvm-project/pull/107080