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

llvm-svn: 295499
diff --git a/llvm/lib/CodeGen/LexicalScopes.cpp b/llvm/lib/CodeGen/LexicalScopes.cpp
index 205902b..275d84e 100644
--- a/llvm/lib/CodeGen/LexicalScopes.cpp
+++ b/llvm/lib/CodeGen/LexicalScopes.cpp
@@ -14,14 +14,23 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/CodeGen/LexicalScopes.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/IR/DebugInfo.h"
-#include "llvm/IR/Function.h"
+#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cassert>
+#include <string>
+#include <tuple>
+#include <utility>
+
 using namespace llvm;
 
 #define DEBUG_TYPE "lexicalscopes"
@@ -58,7 +67,6 @@
 void LexicalScopes::extractLexicalScopes(
     SmallVectorImpl<InsnRange> &MIRanges,
     DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap) {
-
   // Scan each instruction and create scopes. First build working set of scopes.
   for (const auto &MBB : *MF) {
     const MachineInstr *RangeBeginMI = nullptr;
@@ -248,7 +256,6 @@
 void LexicalScopes::assignInstructionRanges(
     SmallVectorImpl<InsnRange> &MIRanges,
     DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap) {
-
   LexicalScope *PrevLexicalScope = nullptr;
   for (const auto &R : MIRanges) {
     LexicalScope *S = MI2ScopeMap.lookup(R.first);