[llvm] [VPlan] Add VPIRInstruction, use for exit block live-outs. (PR #100735)

[via llvm-commits]

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@@ -8852,17 +8856,14 @@ static void addLiveOutsForFirstOrderRecurrences(
     // No edge from the middle block to the unique exit block has been inserted
     // and there is nothing to fix from vector loop; phis should have incoming
     // from scalar loop only.
-    if (ExitingValuesToFix.empty())
-      continue;
-    for (User *U : FORPhi->users()) {
-      auto *UI = cast<Instruction>(U);
-      if (UI->getParent() != ExitBB)
+    for (const auto &[IR, V] : ExitingValuesToFix) {
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ayalz wrote:

```suggestion
    for (const auto &[ExitIRI, V] : ExitingValuesToFix) {
```


https://github.com/llvm/llvm-project/pull/100735