merged the patch of [ruby-dev:25232] instead of [ruby-dev:25223].
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@9269 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
BSD seek support from [ruby-dev:25223]. fixed: [ruby-dev:27150]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@9243 b2dd03c8-39d4-4d8f-98ff-823fe69b080e