configure.in: rpath with OPTDIR
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58287 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
configure.in: rpath with OPTDIR
as -L options, when it is given. [ruby-dev:50065] [Bug #13411]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58287 b2dd03c8-39d4-4d8f-98ff-823fe69b080e