Create directory junctions instead of symlinks on windows

lib/puppetlabs_spec_helper/rake_tasks.rb

@@ -246,6 +246,13 @@ def max_thread_limit
     puppet_symlink_available = Puppet::FileSystem.respond_to?(:symlink)
   rescue
   end
+  if is_windows
+    begin
+      require 'win32/dir'
+    rescue LoadError
+      $stderr.puts "win32-dir gem not installed, falling back to executing mklink directly"
+    end
+  end
 
   # git has a race condition creating that directory, that would lead to aborted clone operations
   FileUtils::mkdir_p("spec/fixtures/modules")
@@ -283,8 +290,17 @@ def max_thread_limit
 
   fixtures("symlinks").each do |source, target|
     if is_windows
-      fail "Cannot symlink on Windows unless using at least Puppet 3.5" if !puppet_symlink_available
-      Puppet::FileSystem::exist?(target) || Puppet::FileSystem::symlink(source, target)
+      if puppet_symlink_available
+        Puppet::FileSystem::exist?(target) || Puppet::FileSystem::symlink(source, target)
+      end
+
+      unless File.symlink?(target)
+        if Dir.respond_to?(:create_junction)
+          Dir.create_junction(target, source)
+        else
+          system("call mklink /J \"#{target.gsub('/', '\\')}\" \"#{source.gsub('/', '\\')}\"")
+        end
+      end
     else
       File::exists?(target) || FileUtils::ln_sf(source, target)
     end