message: WindowsFileHandle: follow convention and have this an override
diff: @@ -489,7 +489,7 @@ public:
  WindowsFileHandle(FileSystem &file_system, string path, HANDLE fd)
  : FileHandle(file_system, path), position(0), fd(fd) {
  }
  - virtual ~WindowsFileHandle() {
  + ~WindowsFileHandle() override {
  Close();
  }
  