[llvm] Merge sourcelocation in CSEMIRBuilder::getDominatingInstrForID. (PR #90922)

[Adrian Prantl via llvm-commits]

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@@ -47,8 +47,9 @@ class CSEMIRBuilder : public MachineIRBuilder {
   /// dominates the current insertion point and if not, move it just before the
   /// current insertion point and return it. If not found, return Null
   /// MachineInstrBuilder.
-  MachineInstrBuilder getDominatingInstrForID(FoldingSetNodeID &ID,
-                                              void *&NodeInsertPos);
+  MachineInstrBuilder
+  getDominatingInstrForID(FoldingSetNodeID &ID, void *&NodeInsertPos,
+                          SmallVectorImpl<DILocation *> *Locs = nullptr);
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adrian-prantl wrote:

It would be good to document what the extra parameter is for, since this is not obvious.

https://github.com/llvm/llvm-project/pull/90922