[llvm] [IR] Add new function attribute nocreateundeforpoison (PR #164809)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> that can be used to mark
intrinsics that do not introduce poison, for example simple arithmetic
intrinsics that propagate poison just like a simple arithmetic
instruction.

Does `NoCreateUndefOrPoison` imply `propagating poison`? I think it holds for most of arithmetic intrinsics. If so, we can avoid hardcoding this property in `intrinsicPropagatesPoison`.


https://github.com/llvm/llvm-project/pull/164809