[llvm] [NewGVN] Prevent cyclic dependencies by ensuring Leader has min RPO number (PR #82110)

[Nuno Lopes via llvm-commits]

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@@ -374,9 +381,10 @@ class CongruenceClass {
     if (this == Other)
       return true;
 
-    if (std::tie(StoreCount, RepLeader, RepStoredValue, RepMemoryAccess) !=
-        std::tie(Other->StoreCount, Other->RepLeader, Other->RepStoredValue,
-                 Other->RepMemoryAccess))
+    if (std::tie(StoreCount, RepLeader.first, RepStoredValue,
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nunoplopes wrote:

why not compare the whole RepLeader instead of just .first?

https://github.com/llvm/llvm-project/pull/82110