eval_intern.h: suppress warning by gcc 4.6
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46205 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
eval_intern.h: suppress warning by gcc 4.6
seems to warn false maybe-uninitialized.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46205 b2dd03c8-39d4-4d8f-98ff-823fe69b080e