[llvm] [WIP] Consider datalayout sentinel pointer value for isKnownNonZero check (PR #91769)

[Rana Pratap Reddy via llvm-commits]

ranapratap55 wrote:

This PR adds a new field as sentinel value in the DL string for all unlisted addrspaces. I am looking into ways to use this in the IR optimizations. There are few APIs(knownbits, knownnull, ConstantPointerNull)which needs to be updated to use this change.

https://github.com/llvm/llvm-project/pull/91769