Update ChangeLog.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42235 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Add a frozenness check test for Enumerator::Lazy#initialize.

* test/ruby/test_lazy_enumerator.rb
  (TestLazyEnumerator#test_initialize): Make sure
  Enumerator::Lazy#initialize raises error if the object is
  frozen.  The check was performed by rb_ivar_set() before
  rb_check_frozen() was added to enumerator_init().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42236 b2dd03c8-39d4-4d8f-98ff-823fe69b080e