[InlineOrder] fix the calculation of Cost for CostBenefitPriority (#86630)

getCost() expects that isVariable() is true.
https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/Analysis/InlineCost.h#L146

Co-authored-by: helloguo <[email protected]>

Author: helloguo

llvm/lib/Analysis/InlineOrder.cpp

@@ -114,7 +114,10 @@ class CostBenefitPriority {
   CostBenefitPriority(const CallBase *CB, FunctionAnalysisManager &FAM,
                       const InlineParams &Params) {
     auto IC = getInlineCostWrapper(const_cast<CallBase &>(*CB), FAM, Params);
-    Cost = IC.getCost();
+    if (IC.isVariable())
+      Cost = IC.getCost();
+    else
+      Cost = IC.isNever() ? INT_MAX : INT_MIN;
     StaticBonusApplied = IC.getStaticBonusApplied();
     CostBenefit = IC.getCostBenefit();
   }