[clang] Remove unused includes (NFC)

These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.

Author: kazutakahirata

clang/lib/Analysis/UnsafeBufferUsage.cpp

@@ -30,7 +30,6 @@
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/Support/Casting.h"
 #include <cstddef>
 #include <optional>
 #include <queue>

clang/lib/Basic/LangOptions.cpp

@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Basic/LangOptions.h"
-#include "llvm/ADT/SmallString.h"
 #include "llvm/Support/Path.h"
 
 using namespace clang;

clang/lib/CodeGen/CGBuiltin.cpp

@@ -17,7 +17,6 @@
 #include "CGDebugInfo.h"
 #include "CGObjCRuntime.h"
 #include "CGOpenCLRuntime.h"
-#include "CGPointerAuthInfo.h"
 #include "CGRecordLayout.h"
 #include "CGValue.h"
 #include "CodeGenFunction.h"

clang/lib/CodeGen/CGHLSLRuntime.cpp

@@ -35,7 +35,6 @@
 #include "llvm/Support/Alignment.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormatVariadic.h"
-#include <utility>
 
 using namespace clang;
 using namespace CodeGen;

clang/lib/Edit/EditedSource.cpp

@@ -16,10 +16,8 @@
 #include "clang/Edit/FileOffset.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
-#include <algorithm>
 #include <cassert>
 #include <tuple>
 #include <utility>

clang/lib/ExtractAPI/ExtractAPIConsumer.cpp

@@ -43,7 +43,6 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Error.h"
-#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Regex.h"

clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp

@@ -19,14 +19,12 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/STLFunctionalExtras.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/Support/raw_ostream.h"
 #include <iterator>
 #include <optional>
-#include <type_traits>
 
 using namespace clang;
 using namespace clang::extractapi;

clang/lib/InstallAPI/DiagnosticBuilderWrappers.cpp

@@ -8,7 +8,6 @@
 
 #include "DiagnosticBuilderWrappers.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TextAPI/Platform.h"
 

clang/lib/InstallAPI/DirectoryScanner.cpp

@@ -9,7 +9,6 @@
 #include "clang/InstallAPI/DirectoryScanner.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
-#include "llvm/TextAPI/DylibReader.h"
 
 using namespace llvm;
 using namespace llvm::MachO;

clang/lib/InstallAPI/FileList.cpp

@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/InstallAPI/FileList.h"
-#include "clang/Basic/DiagnosticFrontend.h"
 #include "clang/InstallAPI/FileList.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/Error.h"