[llvm] [DebugInfo][RemoveDIs] Have getInsertionPtAfterDef return an iterator (PR #73149)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -224,7 +224,9 @@ class Instruction : public User,
   /// of cases, e.g. phi nodes or terminators that return values. This function
   /// may return null if the insertion after the definition is not possible,
   /// e.g. due to a catchswitch terminator.
-  Instruction *getInsertionPointAfterDef();
+  std::optional<
+      SymbolTableList<Instruction, ilist_iterator_bits<true>>::iterator>
+  getInsertionPointAfterDef();
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OCHyams wrote:

nit: `std::optional<InstListType::iterator>`

https://github.com/llvm/llvm-project/pull/73149