diff --git a/clang/lib/Frontend/CachedDiagnostics.h b/clang/lib/Frontend/CachedDiagnostics.h
--- a/clang/lib/Frontend/CachedDiagnostics.h
+++ b/clang/lib/Frontend/CachedDiagnostics.h
@@ -11,6 +11,8 @@
 
 #include "clang/Basic/LLVM.h"
 #include "llvm/Support/PrefixMapper.h"
+#include <memory>
+#include <optional>
 
 namespace clang {
 class DiagnosticConsumer;
diff --git a/clang/lib/Frontend/CachedDiagnostics.cpp b/clang/lib/Frontend/CachedDiagnostics.cpp
--- a/clang/lib/Frontend/CachedDiagnostics.cpp
+++ b/clang/lib/Frontend/CachedDiagnostics.cpp
@@ -25,6 +25,7 @@
 #include "llvm/Support/EndianStream.h"
 #include "llvm/Support/StringSaver.h"
 #include "llvm/Support/YAMLTraits.h"
+#include <variant>
 
 using namespace clang;
 using namespace clang::cas;
diff --git a/llvm/include/llvm/Support/Format.h b/llvm/include/llvm/Support/Format.h
--- a/llvm/include/llvm/Support/Format.h
+++ b/llvm/include/llvm/Support/Format.h
@@ -28,6 +28,7 @@
 #include "llvm/Support/DataTypes.h"
 #include <cassert>
 #include <cstdio>
+#include <optional>
 #include <tuple>
 #include <utility>
 
diff --git a/llvm/include/llvm/TargetParser/SubtargetFeature.h b/llvm/include/llvm/TargetParser/SubtargetFeature.h
--- a/llvm/include/llvm/TargetParser/SubtargetFeature.h
+++ b/llvm/include/llvm/TargetParser/SubtargetFeature.h
@@ -17,6 +17,7 @@
 #ifndef LLVM_TARGETPARSER_SUBTARGETFEATURE_H
 #define LLVM_TARGETPARSER_SUBTARGETFEATURE_H
 
+#include "llvm/ADT/bit.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"