Really fix ARM build (this time verified locally.)

src/cpu-profiler.h

Index: src/cpu-profiler.h
diff --git a/src/cpu-profiler.h b/src/cpu-profiler.h
index 7a3711ddf54637b581a6641429cc6a1f7f3565ed..f9bad4596ec557a766718ff7102a8ec4d95f15d8 100644
--- a/src/cpu-profiler.h
+++ b/src/cpu-profiler.h
@@ -111,8 +111,11 @@ class TickSampleEventRecord {
   unsigned order;
 
 #if defined(__GNUC__) && (__GNUC__ < 4)
-  // Added to avoid 'all member functions in class are private' error.
+  // Added to avoid 'all member functions in class are private' warning.
   INLINE(unsigned get_order() const) { return order; }
+  // Added to avoid 'class only defines private constructors and
+  // has no friends' warning.
+  friend class TickSampleEventRecordFriend;
 #endif
  private:
   // Disable instantiation.