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

llvm-svn: 289475
diff --git a/llvm/lib/Target/AMDGPU/R600FrameLowering.cpp b/llvm/lib/Target/AMDGPU/R600FrameLowering.cpp
index dd5681f..5813786 100644
--- a/llvm/lib/Target/AMDGPU/R600FrameLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/R600FrameLowering.cpp
@@ -11,5 +11,4 @@
 
 using namespace llvm;
 
-R600FrameLowering::~R600FrameLowering() {
-}
+R600FrameLowering::~R600FrameLowering() = default;