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

llvm-svn: 296413
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp
index e63e289..76dd2e4 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp
@@ -1,4 +1,4 @@
-//===-- DWARFDebugAbbrev.cpp ----------------------------------------------===//
+//===- DWARFDebugAbbrev.cpp -----------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -10,6 +10,10 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cinttypes>
+#include <cstdint>
+
 using namespace llvm;
 
 DWARFAbbreviationDeclarationSet::DWARFAbbreviationDeclarationSet() {