Remove unused declarations

[ruiu]

LGTM

COFF/Driver.h

 namespace coff {
 
 class LinkerDriver;
 extern LinkerDriver *Driver;
 
 using llvm::COFF::MachineTypes;
 using llvm::COFF::WindowsSubsystem;
 using llvm::Optional;
-class InputFile;
 
 // Implemented in MarkLive.cpp.
 void markLive(const std::vector<Chunk *> &Chunks);
 
 // Implemented in ICF.cpp.
 void doICF(const std::vector<Chunk *> &Chunks);
 
 class ArgParser {

COFF/Writer.cpp

private:
   void createSymbolAndStringTable();
   void openFile(StringRef OutputPath);
   template <typename PEHeaderTy> void writeHeader();
   void fixSafeSEHSymbols();
   void setSectionPermissions();
   void writeSections();
   void sortExceptionTable();
   void writeBuildId();
-  void applyRelocations();
 
   llvm::Optional<coff_symbol16> createSymbol(Defined *D);
   size_t addEntryToStringTable(StringRef Str);
 
   OutputSection *findSection(StringRef Name);
   OutputSection *createSection(StringRef Name);
   void addBaserels(OutputSection *Dest);
   void addBaserelBlocks(OutputSection *Dest, std::vector<Baserel> &V);

ELF/SymbolTable.h

 #include "InputFiles.h"
 #include "LTO.h"
 #include "Strings.h"
 #include "llvm/ADT/CachedHashString.h"
 #include "llvm/ADT/DenseMap.h"
 
 namespace lld {
 namespace elf {
-class Lazy;
+
 struct Symbol;
 
 // SymbolTable is a bucket of all known symbols, including defined,
 // undefined, or lazy symbols (the last one is symbols in archive
 // files whose archive members are not yet loaded).
 //
 // We put all symbols of all files to a SymbolTable, and the
 // SymbolTable selects the "best" symbols if there are name