[llvm] [DebugInfo][RemoveDIs] Support maintaining DPValues in CodeGenPrepare (PR #73660)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -2829,34 +2836,46 @@ class TypePromotionTransaction {
       Instruction *PrevInst;
       BasicBlock *BB;
     } Point;
+    std::optional<DPValue::self_iterator> beforeDPValue = std::nullopt;
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OCHyams wrote:

nit: beforeDPValue -> BeforeDPValue

https://github.com/llvm/llvm-project/pull/73660