Fix bigserial appears with limit 8 for schema dumper

Before:

```ruby
create_table "postgresql_big_serials", force: :cascade do |t|
  t.bigserial "seq", limit: 8, null: false
end
```

After:

```ruby
create_table "postgresql_big_serials", force: :cascade do |t|
  t.bigserial "seq", null: false
end
```

1 files changed, 4 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
index 19761618cf..5cb2bbbf18 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb
@@ -41,6 +41,10 @@ module ActiveRecord
           end
         end
 
+        def schema_limit(column)
+          super unless schema_type(column) == :bigserial
+        end
+
         def schema_expression(column)
           super unless column.serial?
         end