[llvm-branch-commits] [llvm] [mlir] [WIP][IR][Constants] Change the semantic of `ConstantPointerNull` to represent an actual `nullptr` instead of a zero-value pointer (PR #183215)

[Shilei Tian via llvm-branch-commits]

shiltian wrote:

I also want to get feedback on options to represent a real zero-value pointer. This PR stack chose to use `inttoptr 0`, and then changed the printer and parser to recognize it. Is this really the best option? I wonder if there is any alternatives, like introducing a new class or something.

@nikic @arsenm @arichardson 

https://github.com/llvm/llvm-project/pull/183215