add is required

Author: optimisan

llvm/lib/Target/AMDGPU/AMDGPUReserveWWMRegs.h

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