[llvm] [Reassociate] Compute value ranks iteratively (PR #204952)

[Justin Fargnoli via llvm-commits]

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@@ -212,24 +212,79 @@ unsigned ReassociatePass::getRank(Value *V) {
   if (unsigned Rank = ValueRankMap[I])
     return Rank;    // Rank already known?
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justinfargnoli wrote:

Can we delete this as a result of 250-252?

https://github.com/llvm/llvm-project/pull/204952