[AMDGPU, PowerPC, TableGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 289282
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
index 1b56f46..9496773 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
@@ -17,6 +17,13 @@
 
 #include "AMDGPUIntrinsicInfo.h"
 #include "AMDGPUSubtarget.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Support/CodeGen.h"
+#include "llvm/Target/TargetMachine.h"
+#include <memory>
 
 namespace llvm {
 
@@ -37,7 +44,7 @@
                       StringRef FS, TargetOptions Options,
                       Optional<Reloc::Model> RM, CodeModel::Model CM,
                       CodeGenOpt::Level OL);
-  ~AMDGPUTargetMachine();
+  ~AMDGPUTargetMachine() override;
 
   const AMDGPUSubtarget *getSubtargetImpl() const;
   const AMDGPUSubtarget *getSubtargetImpl(const Function &) const override = 0;
@@ -91,6 +98,6 @@
   const SISubtarget *getSubtargetImpl(const Function &) const override;
 };
 
-} // End namespace llvm
+} // end namespace llvm
 
-#endif
+#endif // LLVM_LIB_TARGET_AMDGPU_AMDGPUTARGETMACHINE_H