configure.in: Info.plist workaround

* configure.in: workaround for Info.plist to get rid of `dsymutil`
  crash by wrong files in parent directories.
  [ruby-core:62594] [Bug #9840]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46032 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-05-21

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46033 b2dd03c8-39d4-4d8f-98ff-823fe69b080e