[DebugInfo] Fix some Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 296559
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp b/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
index ebb9961..76354a9 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
@@ -1,4 +1,4 @@
-//===-- DWARFGdbIndex.cpp -------------------------------------------------===//
+//===- DWARFGdbIndex.cpp --------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,10 +7,16 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cassert>
+#include <cinttypes>
+#include <cstdint>
+#include <utility>
 
 using namespace llvm;