[llvm] [VPlan] Introduce child regions as VPlan transform. (PR #129402)

[Florian Hahn via llvm-commits]

================
@@ -98,4 +120,9 @@ void VPlanTransforms::introduceTopLevelVectorLoopRegion(
                                ScalarLatchTerm->getDebugLoc(), "cmp.n");
   Builder.createNaryOp(VPInstruction::BranchOnCond, {Cmp},
                        ScalarLatchTerm->getDebugLoc());
+
+  for (VPBlockBase *HeaderVPBB :
----------------
fhahn wrote:

I moved up the loop to create all regions via the loop (also the top-most).

https://github.com/llvm/llvm-project/pull/129402