[clang] Add #include <optional> (NFC)

This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

clang/include/clang/AST/ASTContext.h

@@ -46,6 +46,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/TinyPtrVector.h"
 #include "llvm/Support/TypeSize.h"
+#include <optional>
 
 namespace llvm {
 

clang/include/clang/AST/ASTImporter.h

@@ -29,6 +29,7 @@
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/AST/ASTImporterSharedState.h

@@ -18,6 +18,7 @@
 #include "clang/AST/ASTImporterLookupTable.h"
 #include "clang/AST/Decl.h"
 #include "llvm/ADT/DenseMap.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/AST/ASTStructuralEquivalence.h

@@ -18,6 +18,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 #include <queue>
 #include <utility>
 

clang/include/clang/AST/AbstractBasicReader.h

@@ -10,6 +10,7 @@
 #define LLVM_CLANG_AST_ABSTRACTBASICREADER_H
 
 #include "clang/AST/DeclTemplate.h"
+#include <optional>
 
 namespace clang {
 namespace serialization {

clang/include/clang/AST/AbstractBasicWriter.h

@@ -11,6 +11,7 @@
 
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclTemplate.h"
+#include <optional>
 
 namespace clang {
 namespace serialization {

clang/include/clang/AST/ComparisonCategories.h

@@ -19,6 +19,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include <array>
 #include <cassert>
+#include <optional>
 #include <vector>
 
 namespace llvm {

clang/include/clang/AST/Decl.h

@@ -46,6 +46,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/AST/DeclTemplate.h

@@ -39,6 +39,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <iterator>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/AST/Expr.h

@@ -36,6 +36,7 @@
 #include "llvm/Support/AtomicOrdering.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/TrailingObjects.h"
+#include <optional>
 
 namespace clang {
   class APValue;

clang/include/clang/AST/ExprCXX.h

@@ -51,6 +51,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <optional>
 
 namespace clang {
 

clang/include/clang/AST/ExprObjC.h

@@ -40,6 +40,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 
 namespace clang {
 

clang/include/clang/AST/ExternalASTSource.h

@@ -30,6 +30,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <iterator>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/AST/FormatString.h

@@ -19,6 +19,7 @@
 #define LLVM_CLANG_AST_FORMATSTRING_H
 
 #include "clang/AST/CanonicalType.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/AST/Mangle.h

@@ -19,6 +19,7 @@
 #include "clang/Basic/ABI.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/Casting.h"
+#include <optional>
 
 namespace llvm {
   class raw_ostream;

clang/include/clang/AST/NSAPI.h

@@ -12,6 +12,7 @@
 #include "clang/Basic/IdentifierTable.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 
 namespace clang {
   class ASTContext;

clang/include/clang/AST/Stmt.h

@@ -36,6 +36,7 @@
 #include <cassert>
 #include <cstddef>
 #include <iterator>
+#include <optional>
 #include <string>
 
 namespace llvm {

clang/include/clang/AST/TemplateBase.h

@@ -30,6 +30,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 
 namespace llvm {
 

clang/include/clang/AST/TemplateName.h

@@ -21,6 +21,7 @@
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/Support/PointerLikeTypeTraits.h"
 #include <cassert>
+#include <optional>
 
 namespace clang {
 

clang/include/clang/AST/Type.h

@@ -50,6 +50,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <optional>
 #include <string>
 #include <type_traits>
 #include <utility>

clang/include/clang/ASTMatchers/ASTMatchFinder.h

@@ -44,6 +44,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Timer.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -90,6 +90,7 @@
 #include <cstddef>
 #include <iterator>
 #include <limits>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>

clang/include/clang/ASTMatchers/ASTMatchersInternal.h

@@ -66,6 +66,7 @@
 #include <cstdint>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <type_traits>

clang/include/clang/ASTMatchers/Dynamic/Parser.h

@@ -42,6 +42,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
+#include <optional>
 #include <utility>
 #include <vector>
 

clang/include/clang/ASTMatchers/Dynamic/Registry.h

@@ -21,6 +21,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>

clang/include/clang/ASTMatchers/Dynamic/VariantValue.h

@@ -22,6 +22,7 @@
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/Optional.h"
 #include <memory>
+#include <optional>
 #include <vector>
 
 namespace clang {

clang/include/clang/Analysis/Analyses/ThreadSafetyTIL.h

@@ -59,6 +59,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <iterator>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/Analysis/AnyCall.h

@@ -16,6 +16,7 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ExprObjC.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Analysis/BodyFarm.h

@@ -18,6 +18,7 @@
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Analysis/CFG.h

@@ -31,6 +31,7 @@
 #include <cstddef>
 #include <iterator>
 #include <memory>
+#include <optional>
 #include <vector>
 
 namespace clang {

clang/include/clang/Analysis/FlowSensitive/DataflowAnalysis.h

@@ -15,6 +15,7 @@
 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_DATAFLOWANALYSIS_H
 
 #include <iterator>
+#include <optional>
 #include <type_traits>
 #include <utility>
 #include <vector>

clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h

@@ -27,6 +27,7 @@
 #include "llvm/Support/Compiler.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <type_traits>
 #include <utility>
 #include <vector>

clang/include/clang/Analysis/FlowSensitive/Solver.h

@@ -18,6 +18,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 
 namespace clang {
 namespace dataflow {

clang/include/clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TYPEERASEDDATAFLOWANALYSIS_H
 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TYPEERASEDDATAFLOWANALYSIS_H
 
+#include <optional>
 #include <utility>
 #include <vector>
 

clang/include/clang/Analysis/MacroExpansionContext.h

@@ -16,6 +16,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Analysis/PathDiagnostic.h

@@ -30,6 +30,7 @@
 #include <list>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
 #include <utility>

clang/include/clang/Analysis/ProgramPoint.h

@@ -24,6 +24,7 @@
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/DataTypes.h"
 #include <cassert>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/Analysis/RetainSummaryManager.h

@@ -25,6 +25,7 @@
 #include "clang/Analysis/AnyCall.h"
 #include "clang/Analysis/SelectorExtras.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 
 using namespace clang;
 

clang/include/clang/Basic/DarwinSDKInfo.h

@@ -15,6 +15,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/Support/VirtualFileSystem.h"
+#include <optional>
 
 namespace llvm {
 namespace json {

clang/include/clang/Basic/Diagnostic.h

@@ -32,6 +32,7 @@
 #include <list>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <type_traits>
 #include <utility>

clang/include/clang/Basic/DiagnosticError.h

@@ -11,6 +11,7 @@
 
 #include "clang/Basic/PartialDiagnostic.h"
 #include "llvm/Support/Error.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Basic/DiagnosticIDs.h

@@ -17,6 +17,7 @@
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/StringRef.h"
+#include <optional>
 #include <vector>
 
 namespace clang {

clang/include/clang/Basic/DirectoryEntry.h

@@ -23,6 +23,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ErrorOr.h"
 
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/Basic/FileEntry.h

@@ -25,6 +25,7 @@
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/FileSystem/UniqueID.h"
 
+#include <optional>
 #include <utility>
 
 namespace llvm {

clang/include/clang/Basic/FileSystemStatCache.h

@@ -23,6 +23,7 @@
 #include <cstdint>
 #include <ctime>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/Basic/LangOptions.h

@@ -24,6 +24,7 @@
 #include "llvm/ADT/FloatingPointMode.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
+#include <optional>
 #include <string>
 #include <vector>
 

clang/include/clang/Basic/Module.h

@@ -33,6 +33,7 @@
 #include <cstdint>
 #include <ctime>
 #include <iterator>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>

clang/include/clang/Basic/ProfileList.h

@@ -20,6 +20,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
 #include <memory>
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Basic/Sarif.h

@@ -43,6 +43,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <initializer_list>
+#include <optional>
 #include <string>
 
 namespace clang {

clang/include/clang/Basic/SourceManager.h

@@ -53,6 +53,7 @@
 #include <cstddef>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>

clang/include/clang/CrossTU/CrossTranslationUnit.h

@@ -23,6 +23,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/Path.h"
+#include <optional>
 
 namespace clang {
 class CompilerInstance;

clang/include/clang/ExtractAPI/Serialization/SymbolGraphSerializer.h

@@ -24,6 +24,7 @@
 #include "llvm/Support/JSON.h"
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 namespace clang {
 namespace extractapi {

clang/include/clang/Format/Format.h

@@ -20,6 +20,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/Regex.h"
 #include "llvm/Support/SourceMgr.h"
+#include <optional>
 #include <system_error>
 
 namespace llvm {

clang/include/clang/Frontend/ASTUnit.h

@@ -41,6 +41,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>

clang/include/clang/Frontend/CommandLineSourceLoc.h

@@ -17,6 +17,7 @@
 #include "clang/Basic/LLVM.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Frontend/CompilerInstance.h

@@ -26,6 +26,7 @@
 #include <cassert>
 #include <list>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/Frontend/FrontendOptions.h

@@ -19,6 +19,7 @@
 #include <cassert>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <vector>
 

clang/include/clang/Lex/HeaderMap.h

@@ -21,6 +21,7 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <memory>
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Lex/Lexer.h

@@ -24,6 +24,7 @@
 #include "llvm/ADT/StringRef.h"
 #include <cassert>
 #include <cstdint>
+#include <optional>
 #include <string>
 
 namespace llvm {

clang/include/clang/Lex/ModuleMap.h

@@ -30,6 +30,7 @@
 #include "llvm/ADT/Twine.h"
 #include <ctime>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/Lex/PreprocessingRecord.h

@@ -29,6 +29,7 @@
 #include <cassert>
 #include <cstddef>
 #include <iterator>
+#include <optional>
 #include <utility>
 #include <vector>
 

clang/include/clang/Lex/Preprocessor.h

@@ -51,6 +51,7 @@
 #include <cstdint>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>

clang/include/clang/Lex/PreprocessorOptions.h

@@ -18,6 +18,7 @@
 #include <functional>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
 #include <utility>

clang/include/clang/Parse/Parser.h

@@ -28,6 +28,7 @@
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/SaveAndRestore.h"
 #include <memory>
+#include <optional>
 #include <stack>
 
 namespace clang {

clang/include/clang/Sema/CodeCompleteConsumer.h

@@ -29,6 +29,7 @@
 #include "llvm/Support/type_traits.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/Sema/Lookup.h

@@ -30,6 +30,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Casting.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/Sema/Scope.h

@@ -20,6 +20,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/iterator_range.h"
 #include <cassert>
+#include <optional>
 
 namespace llvm {
 

clang/include/clang/Sema/Sema.h

@@ -68,6 +68,7 @@
 #include "llvm/Frontend/OpenMP/OMPConstants.h"
 #include <deque>
 #include <memory>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <vector>

clang/include/clang/Sema/SemaConcept.h

@@ -20,6 +20,7 @@
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/Sema/SemaLambda.h

@@ -16,6 +16,7 @@
 #define LLVM_CLANG_SEMA_SEMALAMBDA_H
 
 #include "clang/AST/ASTLambda.h"
+#include <optional>
 
 namespace clang {
 namespace sema {

clang/include/clang/Sema/Template.h

@@ -23,6 +23,7 @@
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/SmallVector.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/Sema/TemplateDeduction.h

@@ -26,6 +26,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include <cassert>
 #include <cstddef>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/Serialization/ASTReader.h

@@ -57,6 +57,7 @@
 #include <ctime>
 #include <deque>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
 #include <utility>

clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h

@@ -38,6 +38,7 @@
 #include "llvm/ADT/iterator_range.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>

clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h

@@ -25,6 +25,7 @@
 #include "llvm/ADT/StringRef.h"
 #include <list>
 #include <memory>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h

@@ -19,6 +19,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/Support/Compiler.h"
+#include <optional>
 #include <vector>
 
 namespace clang {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h

@@ -45,6 +45,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <limits>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h

@@ -16,6 +16,7 @@
 
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
+#include <optional>
 
 namespace clang {
 namespace ento {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h

@@ -17,6 +17,7 @@
 #include "clang/AST/Stmt.h"
 #include "clang/Basic/OperatorKinds.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 #include <tuple>
 
 namespace clang {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h

@@ -20,6 +20,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/Support/SaveAndRestore.h"
 #include <memory>
+#include <optional>
 #include <utility>
 
 namespace llvm {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h

@@ -38,6 +38,7 @@
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <utility>
 #include <vector>
 

clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h

@@ -36,6 +36,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h"
 #include "llvm/ADT/ArrayRef.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h

@@ -21,6 +21,7 @@
 #include "llvm/ADT/SmallBitVector.h"
 #include <cassert>
 #include <deque>
+#include <optional>
 #include <utility>
 
 namespace clang {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h

@@ -37,6 +37,7 @@
 #include <cassert>
 #include <cstdint>
 #include <limits>
+#include <optional>
 #include <string>
 #include <utility>
 

clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h

@@ -23,6 +23,7 @@
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/ImmutableMap.h"
 #include "llvm/Support/Allocator.h"
+#include <optional>
 #include <utility>
 
 namespace llvm {

clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h

@@ -18,6 +18,7 @@
 #include "clang/Basic/TargetInfo.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SMTConv.h"
+#include <optional>
 
 typedef llvm::ImmutableSet<
     std::pair<clang::ento::SymbolRef, const llvm::SMTExpr *>>

clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h

@@ -30,6 +30,7 @@
 #include "llvm/ADT/ImmutableList.h"
 #include "llvm/ADT/Optional.h"
 #include <cstdint>
+#include <optional>
 
 namespace clang {
 

clang/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h

@@ -25,6 +25,7 @@
 #include "llvm/Support/Casting.h"
 #include <cassert>
 #include <cstdint>
+#include <optional>
 #include <utility>
 
 //==------------------------------------------------------------------------==//

clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h

@@ -28,6 +28,7 @@
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <optional>
 
 namespace clang {
 

clang/include/clang/Tooling/ASTDiff/ASTDiff.h

@@ -20,6 +20,7 @@
 #define LLVM_CLANG_TOOLING_ASTDIFF_ASTDIFF_H
 
 #include "clang/Tooling/ASTDiff/ASTDiffInternal.h"
+#include <optional>
 
 namespace clang {
 namespace diff {

clang/include/clang/Tooling/AllTUsExecution.h

@@ -16,6 +16,7 @@
 
 #include "clang/Tooling/ArgumentsAdjusters.h"
 #include "clang/Tooling/Execution.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {

clang/include/clang/Tooling/Core/Replacement.h

@@ -26,6 +26,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/raw_ostream.h"
 #include <map>
+#include <optional>
 #include <set>
 #include <string>
 #include <system_error>

clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h

@@ -17,6 +17,7 @@
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include <mutex>
+#include <optional>
 
 namespace clang {
 namespace tooling {

clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h

@@ -16,6 +16,7 @@
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/StringMap.h"
+#include <optional>
 #include <string>
 #include <vector>
 

clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h

@@ -17,6 +17,7 @@
 #include "clang/Tooling/DependencyScanning/ModuleDepCollector.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FileSystem.h"
+#include <optional>
 #include <string>
 
 namespace clang {

clang/include/clang/Tooling/Inclusions/HeaderIncludes.h

@@ -15,6 +15,7 @@
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Regex.h"
 #include <list>
+#include <optional>
 #include <unordered_map>
 
 namespace clang {

clang/include/clang/Tooling/Refactoring/ASTSelection.h

@@ -14,6 +14,7 @@
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceLocation.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 #include <vector>
 
 namespace clang {

clang/include/clang/Tooling/Refactoring/Extract/Extract.h

@@ -11,6 +11,7 @@
 
 #include "clang/Tooling/Refactoring/ASTSelection.h"
 #include "clang/Tooling/Refactoring/RefactoringActionRules.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {

clang/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h

@@ -10,6 +10,7 @@
 #define LLVM_CLANG_TOOLING_REFACTORING_REFACTORINGOPTIONVISITOR_H
 
 #include "clang/Basic/LLVM.h"
+#include <optional>
 #include <type_traits>
 
 namespace clang {

clang/include/clang/Tooling/Refactoring/RefactoringOptions.h

@@ -14,6 +14,7 @@
 #include "clang/Tooling/Refactoring/RefactoringOption.h"
 #include "clang/Tooling/Refactoring/RefactoringOptionVisitor.h"
 #include "llvm/Support/Error.h"
+#include <optional>
 #include <type_traits>
 
 namespace clang {