Add missing test for atexit test suite.

Change-Id: I3d14d7df1da53ccef534c106633593551ab6a7cb
diff --git a/tests/atexit_testlib.cpp b/tests/atexit_testlib.cpp
index 36393e7..1fefdf0 100644
--- a/tests/atexit_testlib.cpp
+++ b/tests/atexit_testlib.cpp
@@ -22,19 +22,20 @@
 static std::string* atexit_sequence = NULL;
 static bool* atexit_valid_this_in_static_dtor = NULL;
 
-class AtExitStaticClass;
-
-static const AtExitStaticClass* valid_this = NULL;
-
 static class AtExitStaticClass {
-public:
-  AtExitStaticClass() { valid_this = this; }
+ public:
+  AtExitStaticClass() { expected_this = this; }
   ~AtExitStaticClass() {
     if (atexit_valid_this_in_static_dtor) {
-      *atexit_valid_this_in_static_dtor = (valid_this == this);
+      *atexit_valid_this_in_static_dtor = (expected_this == this);
     }
   }
-} staticObj;
+ private:
+  static const AtExitStaticClass* expected_this;
+
+} static_obj;
+
+const AtExitStaticClass* AtExitStaticClass::expected_this = NULL;
 
 // 4
 static void atexit_handler_from_atexit_from_atexit2() {