[llvm] [DenseMap] Do not align pointer sentinel values (NFC) (PR #146595)

[Jakub Kuderski via llvm-commits]

https://github.com/kuhar commented:

Do you know if this runs into issues with undefined behavior? I don't know the exact rules, but remember reading something along the lines that some OOB pointers cannot even be compared without running into UB. Having pointers that don't respect type alignment sounds like walking on thin ice to me...

https://github.com/llvm/llvm-project/pull/146595