add isRequired()

Author: optimisan

llvm/include/llvm/CodeGen/InitUndef.h

@@ -17,6 +17,7 @@ class InitUndefPass : public PassInfoMixin<InitUndefPass> {
 public:
   PreservedAnalyses run(MachineFunction &MF,
                         MachineFunctionAnalysisManager &MFAM);
+  static bool isRequired() { return true; }
 };
 
 } // namespace llvm