Inject tsort path before rdoc

Author: hsbt

tool/rdoc-srcdir

@@ -1,7 +1,9 @@
 #!ruby -W0
 
-rdoc_path = Dir.glob("#{File.dirname(__dir__)}/.bundle/gems/rdoc-*").first
-$LOAD_PATH.unshift("#{rdoc_path}/lib")
+%w[tsort rdoc].each do |lib|
+  path = Dir.glob("#{File.dirname(__dir__)}/.bundle/gems/#{lib}-*").first
+  $LOAD_PATH.unshift("#{path}/lib")
+end
 require 'rdoc/rdoc'
 
 # Make only the output directory relative to the invoked directory.