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

[Rana Pratap Reddy via llvm-commits]

ranapratap55 wrote:

> I think I'd rather just leave ConstantPointerNull as meaning the all-zero bit pattern. Some places actually do care that it's all-zero, and there's not much benefit to changing it. But better to discuss that on an RFC, probably.

sure, will look into it and will start an RFC with more details.

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