default.mspec: limit cores
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59103 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
default.mspec: limit cores
number of processors, not to acquire tokens more than necessary.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59103 b2dd03c8-39d4-4d8f-98ff-823fe69b080e