[llvm] [SelectionDAG] Change computeAliasing signature from optional<uint64> to LocationSize. (PR #83017)

[via llvm-commits]

llvmbot wrote:

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Failed to cherry-pick: ea5aad7ca37e557e7d6cf0746c9f94f7fe3ce28c

https://github.com/llvm/llvm-project/actions/runs/8139146145

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/83017