[AArch64] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 292996
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index 65e9469..5cce8f9 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -90,21 +90,42 @@
 #include "AArch64FrameLowering.h"
 #include "AArch64InstrInfo.h"
 #include "AArch64MachineFunctionInfo.h"
+#include "AArch64RegisterInfo.h"
 #include "AArch64Subtarget.h"
 #include "AArch64TargetMachine.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/CodeGen/LivePhysRegs.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/CallingConv.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/Function.h"
+#include "llvm/MC/MCDwarf.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
+#include <cassert>
+#include <cstdint>
+#include <iterator>
+#include <vector>
 
 using namespace llvm;
 
@@ -319,7 +340,6 @@
 static MachineBasicBlock::iterator convertCalleeSaveRestoreToSPPrePostIncDec(
     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
     const DebugLoc &DL, const TargetInstrInfo *TII, int CSStackSizeInc) {
-
   unsigned NewOpc;
   bool NewIsUnscaled = false;
   switch (MBBI->getOpcode()) {
@@ -870,15 +890,19 @@
 }
 
 namespace {
+
 struct RegPairInfo {
-  RegPairInfo() : Reg1(AArch64::NoRegister), Reg2(AArch64::NoRegister) {}
-  unsigned Reg1;
-  unsigned Reg2;
+  unsigned Reg1 = AArch64::NoRegister;
+  unsigned Reg2 = AArch64::NoRegister;
   int FrameIdx;
   int Offset;
   bool IsGPR;
+
+  RegPairInfo() = default;
+
   bool isPaired() const { return Reg2 != AArch64::NoRegister; }
 };
+
 } // end anonymous namespace
 
 static void computeCalleeSaveRegisterPairs(