Address test_pluck_columns_with_same_name failure due to nondetermini…

…stic sort order

```ruby
$ bundle exec rake test_postgresql
... snip ...
Failure:
CalculationsTest#test_pluck_columns_with_same_name [/home/yahonda/git/rails/activerecord/test/cases/calculations_test.rb:842]:
--- expected
+++ actual
@@ -1 +1 @@
-[["The First Topic", "The Second Topic of the day"], ["The Third Topic of the day", "The Fourth Topic of the day"]]
+[["The Third Topic of the day", "The Fourth Topic of the day"], ["The First Topic", "The Second Topic of the day"]]
```

activerecord/test/cases/calculations_test.rb

@@ -837,7 +837,7 @@ def test_pluck_replaces_select_clause
 
   def test_pluck_columns_with_same_name
     expected = [["The First Topic", "The Second Topic of the day"], ["The Third Topic of the day", "The Fourth Topic of the day"]]
-    actual = Topic.joins(:replies)
+    actual = Topic.joins(:replies).order(:id)
       .pluck("topics.title", "replies_topics.title")
     assert_equal expected, actual
   end