[llvm] [InferAddressSpaces] Do not commute ptrmask with cast when it may not preserve null (PR #219472)

[Robert Imschweiler via llvm-commits]

https://github.com/ro-i commented:

so, I guess "later" is now :) https://github.com/llvm/llvm-project/pull/140802#discussion_r2535384776

https://github.com/llvm/llvm-project/pull/219472