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

[Jay Foad 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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jayfoad wrote:

Why does this take MBB instead of MF?

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