[llvm] [VPlan] Construct initial once and pass clones to tryToBuildVPlan (NFC). (PR #141363)

[via llvm-commits]

================
@@ -8715,11 +8715,13 @@ void LoopVectorizationPlanner::buildVPlansWithVPRecipes(ElementCount MinVF,
     // overlap across all iterations.
     LVer.prepareNoAliasMetadata();
   }
+  auto VPlan0 = VPlanTransforms::buildPlainCFG(OrigLoop, *LI);
----------------
ayalz wrote:

```suggestion

  auto VPlan0 = VPlanTransforms::buildPlainCFG(OrigLoop, *LI);
```

https://github.com/llvm/llvm-project/pull/141363