Avoid using invalid addresses in ListsTestCase too

This is similar to the previous commit, but done in a slightly different
way to avoid changing too much of the existing code: just make "i" an
alias for the first array element to ensure that "&i + 4" is a valid
pointer.

tests/lists/lists.cpp

@@ -114,7 +114,8 @@ void ListsTestCase::wxStdListTest()
     wxListInt list1;
     wxListInt::iterator it, en;
     wxListInt::reverse_iterator rit, ren;
-    int i;
+    int buf[4];
+    int& i = buf[0];
     for ( i = 0; i < 5; ++i )
         list1.push_back(i + &i);