[llvm] [DA] Add initial support for monotonicity check (PR #162280)

[Ryotaro Kasuga via llvm-commits]

kasuga-fj wrote:

@amehsan JFYI: [This commit message](https://github.com/llvm/llvm-project/commit/a353e258ba495be58263d6cc6e382e6dde298361) really helped me understand the nusw-based inference in LAA.

https://github.com/llvm/llvm-project/pull/162280