This patch teaches MachinePipeliner.h to include
DFAPacketizer.h so that the header file is self contained.
Without this patch, a C++ source file that only includes
MachinePipeliner.h does not compile because the forward declaration of
DFAPacketizer is not enough for:
llvm::SmallVector<std::unique_ptr<DFAPacketizer>> DFAResources;
#define LLVM_CODEGEN_MACHINEPIPELINER_H
#include "llvm/ADT/SetVector.h"
+#include "llvm/CodeGen/DFAPacketizer.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
#include "llvm/CodeGen/RegisterClassInfo.h"