[PATCH] ActiveSupport::OrderedHash#each* methods don't return self

I noticed while using Enumerable#group_by that ordered hashes don't act like normal hashes. Specifically, their each* methods return their keys instead of self:

>> h = ActiveSupport::OrderedHash.new.merge :a =>1, :b =>2
=> #<OrderedHash {:a=>1, :b=>2}>
>> h.each { }
=> [:a, :b]
>> h.each_key { }
=> [:a, :b]
>> h.each_value { }
=> [:a, :b]

Breaking compatibility with Hash is not good as it leads to unexpected and broken behavior. It also seems these methods were made with the intention of Hash compatibility.