merges r22081 from trunk into ruby_1_9_1.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@22514 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merges r22081 from trunk into ruby_1_9_1.
of #elif. a patch from NISHIMATSU Takeshi <t_nissie at yahoo.co.jp>
in [ruby-list:45856].
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@22514 b2dd03c8-39d4-4d8f-98ff-823fe69b080e