Fix `JoinDependency` with using a custom table

Without this fix, `JoinDependency` doesn't use a custom table alias:

```
% ARCONN=sqlite3 be ruby -w -Itest test/cases/relations_test.rb -n test_using_a_custom_table_with_joins_affects_the_wheres
Using sqlite3
Run options: -n test_using_a_custom_table_with_joins_affects_the_wheres --seed 14531

E

Error:RelationTest#test_using_a_custom_table_with_joins_affects_the_wheres:
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: posts.author_id: SELECT  "omg_posts".* FROM "posts" "omg_posts" INNER JOIN "authors" ON "authors"."id" = "posts"."author_id" WHERE "omg_posts"."title" = ? LIMIT ?
```

1 files changed, 4 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/relation/merger.rb b/activerecord/lib/active_record/relation/merger.rb
index 5dac00724a..6251f6fc33 100644
--- a/activerecord/lib/active_record/relation/merger.rb
+++ b/activerecord/lib/active_record/relation/merger.rb
@@ -119,9 +119,10 @@ module ActiveRecord
               end
             end
 
-            join_dependency = ActiveRecord::Associations::JoinDependency.new(other.klass,
-                                                                             joins_dependency,
-                                                                             [])
+            join_dependency = ActiveRecord::Associations::JoinDependency.new(
+              other.klass, other.table, joins_dependency, []
+            )
+
             relation.joins! rest
 
             @relation = relation.joins join_dependency