[llvm] [MachineBasicBlock] Fix use after free in SplitCriticalEdge (PR #68786)

[Matthias Braun via llvm-commits]

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@@ -1097,6 +1097,31 @@ static bool jumpTableHasOtherUses(const MachineFunction &MF,
   return false;
 }
 
+class MBBSplitCriticalEdgeDelegate : public MachineFunction::Delegate {
+private:
+  MachineFunction *MF;
+  SlotIndexes *Indexes;
+
+public:
+  MBBSplitCriticalEdgeDelegate(MachineBasicBlock *MBB,
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MatzeB wrote:

Consider using references for non-null things.

https://github.com/llvm/llvm-project/pull/68786