Adds test for plugin autoloading plugins issue (#36320).

Patch by @tohosaku.

git-svn-id: https://svn.redmine.org/redmine/trunk@22508 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/lib/redmine/plugin_loader_test.rb

@@ -56,6 +56,10 @@ class Redmine::PluginLoaderTest < ActiveSupport::TestCase
     assert File.exist?("#{@klass.public_directory}/foo_plugin/stylesheets/foo.css")
   end
 
+  def test_autoload
+    assert_equal true, Object.const_defined?(:Foo)
+  end
+
   def clear_public
     FileUtils.rm_rf 'tmp/public'
   end