[llvm] [LVI] Handle constant value lattice in `getEdgeValueLocal` (PR #161410)

[Nikita Popov via llvm-commits]

nikic wrote:

@andjo403 There is a separate lattice value for `!=` cases that can't be expressed as a range. Mostly used for `!= null`.

https://github.com/llvm/llvm-project/pull/161410