[llvm] [VPlan] Hook IR blocks into VPlan during skeleton creation (NFC) (PR #114292)

[via llvm-commits]

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@@ -4135,10 +4129,6 @@ class VPBlockUtils {
                             unsigned PredIdx = -1u, unsigned SuccIdx = -1u) {
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ayalz wrote:

Are these indices still needed/used?

https://github.com/llvm/llvm-project/pull/114292