rails/rails — pull request #8266 by CvX (2012-11-19 01:11:12+00:00)
Title: Add rename_index to change_table.

With this change `rename_index` can be used inside a `change_table` block.
Example:

```ruby
change_table :accounts do |t|
t.rename_index :user_id, :account_id
end
```

I believe it was the only schema transforming method that wasn't available inside `change_table`.