* lib/ostruct.rb (OpenStruct#new_ostruct_member): checks if frozen.
	  [ruby-talk:328195], [ruby-core:22142]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_7@23581 b2dd03c8-39d4-4d8f-98ff-823fe69b080e