message: Explicitly include FileSystem.h and use not depricated version of F_Text
diff: #include <llvm/Support/CommandLine.h>
  #include <llvm/Support/Debug.h>
  +#include <llvm/Support/FileSystem.h>
  #include <llvm/Support/Signals.h>
  #include <llvm/Support/TargetRegistry.h>
  #include <llvm/Support/TargetSelect.h>
  @@ -471,7 +472,7 @@ static void setCallingConv(VectorCallStatus vectorCall, Arch arch) {
  static void writeCompileTimeFile(const char *outFileName) {
  llvm::SmallString<128> jsonFileName(outFileName);
  jsonFileName.append(".json");
  - llvm::sys::fs::OpenFlags flags = llvm::sys::fs::F_Text;
  + llvm::sys::fs::OpenFlags flags = llvm::sys::fs::OF_Text;
  std::error_code error;
  std::unique_ptr<llvm::ToolOutputFile> of(new llvm::ToolOutputFile(jsonFileName.c_str(), error, flags));
  