git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@31852 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merges r30542 from trunk into ruby_1_9_2. Fixes #4279.¶
ASCII-8BIT encoding (and ENC_CODERANGE_VALID). [ruby-core:34482]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@31852 b2dd03c8-39d4-4d8f-98ff-823fe69b080e