Implicit through table joins should be appeared before user supplied joins

#36293 was an issue for through association with `joins` for a long
time, but since #35864 through association with `left_joins` would also
be affected by the issue.

Implicit through table joins should be appeared before user supplied
joins, otherwise loading through association with joins will cause a
statement invalid error.

Fixes #36293.

```
% ARCONN=postgresql bundle exec ruby -w -Itest test/cases/associations/has_many_through_associations_test
.rb -n test_through_association_with_joins
Using postgresql
Run options: -n test_through_association_with_joins --seed 7116

# Running:

E

Error:
HasManyThroughAssociationsTest#test_through_association_with_joins:
ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR:  missing FROM-clause entry for table "posts"
LINE 1: ... "comments_posts" ON "comments_posts"."post_id" = "posts"."i...
                                                             ^
: SELECT "comments".* FROM "comments" INNER JOIN "comments" "comments_posts" ON "comments_posts"."post_id" = "posts"."id" INNER JOIN "posts" ON "comments"."post_id" = "posts"."id" WHERE "posts"."author_id" = $1

rails test test/cases/associations/has_many_through_associations_test.rb:61

Finished in 0.388657s, 2.5730 runs/s, 0.0000 assertions/s.
1 runs, 0 assertions, 0 failures, 1 errors, 0 skips
```

1 files changed, 8 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/has_many_through_associations_test.rb b/activerecord/test/cases/associations/has_many_through_associations_test.rb
index 0ab99aa6cd..affa024d77 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -58,6 +58,14 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal preloaded, Marshal.load(Marshal.dump(preloaded))
   end
 
+  def test_through_association_with_joins
+    assert_equal [comments(:eager_other_comment1)], authors(:mary).comments.merge(Post.joins(:comments))
+  end
+
+  def test_through_association_with_left_joins
+    assert_equal [comments(:eager_other_comment1)], authors(:mary).comments.merge(Post.left_joins(:comments))
+  end
+
   def test_preload_with_nested_association
     posts = Post.preload(:author, :author_favorites_with_scope).to_a