[llvm] [ValueTracking] Fixup bugprone logic in non-zero of `select`/`phi`; NFC (PR #69623)

[via llvm-commits]

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@@ -2666,15 +2666,21 @@ static bool isKnownNonZeroFromOperator(const Operator *I,
 
       // The condition of the select dominates the true/false arm. Check if the
       // condition implies that a given arm is non-zero.
-      Value *X;
+      Value *X, *Y;
       CmpInst::Predicate Pred;
-      if (!match(I->getOperand(0), m_c_ICmp(Pred, m_Specific(Op), m_Value(X))))
+      if (!match(I->getOperand(0), m_ICmp(Pred, m_Value(X), m_Value(Y))))
+        return false;
+      if (Y == Op) {
+        Pred = ICmpInst::getSwappedPredicate(Pred);
+        std::swap(X, Y);
+      }
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goldsteinn wrote:

:/ forgot that `m_c_ICmp` does the pred swapping for us

https://github.com/llvm/llvm-project/pull/69623