[ValueTracking] Add missing check for two-value PN recurrance matching

When InstTy is a type like IntrinsicInst which can have a variable number of
arguments, we can encounter a case where Opetaion will have fewer than two
arguments and error at the getOperand() calls.

Author: ivanradanov

llvm/lib/Analysis/ValueTracking.cpp

@@ -9147,7 +9147,8 @@ static bool matchTwoInputRecurrence(const PHINode *PN, InstTy *&Inst,
     return false;
 
   for (unsigned I = 0; I != 2; ++I) {
-    if (auto *Operation = dyn_cast<InstTy>(PN->getIncomingValue(I))) {
+    if (auto *Operation = dyn_cast<InstTy>(PN->getIncomingValue(I));
+        Operation && Operation->getNumOperands() == 2) {
       Value *LHS = Operation->getOperand(0);
       Value *RHS = Operation->getOperand(1);
       if (LHS != PN && RHS != PN)