[llvm] [VPlan] Only skip expansion for SCEVUnknown if it isn't an instruction. (PR #125235)

[Nikita Popov via llvm-commits]

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@@ -3335,7 +3335,7 @@ void VPExpandSCEVRecipe::execute(VPTransformState &State) {
   }
 
   const DataLayout &DL = State.CFG.PrevBB->getDataLayout();
-  SCEVExpander Exp(SE, DL, "induction");
+  SCEVExpander Exp(SE, DL, "induction", true);
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nikic wrote:

```suggestion
  SCEVExpander Exp(SE, DL, "induction", /*PreserveLCSSA=*/true);
```

https://github.com/llvm/llvm-project/pull/125235