configure.in: multiple opt-dir
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37242 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
configure.in: multiple opt-dir
$PATH_SEPARATOR as well as dir_config in mkmf.rb. [ruby-core:47868]
[Bug #7120]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37242 b2dd03c8-39d4-4d8f-98ff-823fe69b080e