Bring in google3-style DISALLOW_* macros.

I've been meaning to do this for a very long time...

Change-Id: Ia8c16eee7c026c3c9505399948485fb778fb0152

libc/private/ScopedReaddir.h

@@ -19,6 +19,8 @@
 
 #include <dirent.h>
 
+#include "private/bionic_macros.h"
+
 class ScopedReaddir {
  public:
   ScopedReaddir(const char* path) {
@@ -42,9 +44,7 @@ class ScopedReaddir {
  private:
   DIR* dir_;
 
-  // Disallow copy and assignment.
-  ScopedReaddir(const ScopedReaddir&);
-  void operator=(const ScopedReaddir&);
+  DISALLOW_COPY_AND_ASSIGN(ScopedReaddir);
 };
 
 #endif // SCOPED_READDIR_H