array.c: freeze in callback ยท ruby/ruby@7fa5e60

* array.c (rb_ary_uniq_bang): must not be modified once frozen even in a callback method. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41247 b2dd03c8-39d4-4d8f-98ff-823fe69b080e