[llvm] [SelectionDAG] Preserve cache hint metadata through DAGCombiner (PR #225954)

[Yonah Goldberg via llvm-commits]

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YonahGoldberg wrote:

Yeah unfortunately update_mir_test_checks.py doesn't have --check-globals option so I need to manually add the checks.

https://github.com/llvm/llvm-project/pull/225954