[llvm] [JumpThreading] NFC: Add comment referencing #199408. (PR #199718)

[Justin Lebar via llvm-commits]

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@@ -2789,6 +2789,13 @@ void JumpThreadingPass::unfoldSelectInstr(BasicBlock *Pred, BasicBlock *BB,
   PredTerm->removeFromParent();
   PredTerm->insertInto(NewBB, NewBB->end());
   // Create a conditional branch and update PHI nodes.
+  //
+  // Note: Technically we should `freeze` the condition before using it in a
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jlebar wrote:

Done

https://github.com/llvm/llvm-project/pull/199718