[llvm] [DebugInfo][RemoveDIs] Emulate inserting insts in dbg.value sequences (PR #73350)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -267,6 +267,19 @@ void DPMarker::dropOneDPValue(DPValue *DPV) {
   DPV->deleteInstr();
 }
 
+std::optional<DPValue::self_iterator> DPMarker::getReinsertionPosition() {
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OCHyams wrote:

Does this need to be a `DPMarker` method? It doesn't look like any members are used other than `MarkedInstr`, which I imagine can be found easily at call sites.

The use-case in #73660 looks like it creates a DPMarker just to call this function (I could be misreading it though?).

https://github.com/llvm/llvm-project/pull/73350