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

llvm-svn: 313823
diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
index 0c94368..99353a3 100644
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
@@ -1,4 +1,4 @@
-//===-- ARMTargetTransformInfo.h - ARM specific TTI -------------*- C++ -*-===//
+//===- ARMTargetTransformInfo.h - ARM specific TTI --------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -6,28 +6,43 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
 /// \file
 /// This file a TargetTransformInfo::Concept conforming object specific to the
 /// ARM target machine. It uses the target's detailed information to
 /// provide more precise answers to certain TTI queries, while letting the
 /// target independent and default TTI implementations handle the rest.
-///
+//
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_TARGET_ARM_ARMTARGETTRANSFORMINFO_H
 #define LLVM_LIB_TARGET_ARM_ARMTARGETTRANSFORMINFO_H
 
 #include "ARM.h"
+#include "ARMSubtarget.h"
 #include "ARMTargetMachine.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/CodeGen/BasicTTIImpl.h"
-#include "llvm/Target/TargetLowering.h"
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/Function.h"
+#include "llvm/MC/SubtargetFeature.h"
 
 namespace llvm {
 
+class APInt;
+class ARMTargetLowering;
+class Instruction;
+class Loop;
+class SCEV;
+class ScalarEvolution;
+class Type;
+class Value;
+
 class ARMTTIImpl : public BasicTTIImplBase<ARMTTIImpl> {
-  typedef BasicTTIImplBase<ARMTTIImpl> BaseT;
-  typedef TargetTransformInfo TTI;
+  using BaseT = BasicTTIImplBase<ARMTTIImpl>;
+  using TTI = TargetTransformInfo;
+
   friend BaseT;
 
   const ARMSubtarget *ST;
@@ -175,4 +190,4 @@
 
 } // end namespace llvm
 
-#endif
+#endif // LLVM_LIB_TARGET_ARM_ARMTARGETTRANSFORMINFO_H