objects didn't get positions

positions.empty? was wrong check

test/risc/test_text_writer.rb

@@ -33,6 +33,7 @@ module Risc
       sorted_objects = @text_writer.sorted_objects
       sorted_objects.each_slice(2) do |l,r|
         next unless r
+        next if l.is_a?(Label) or r.is_a?(Label)
         assert Position.get(l).at < Position.get(r).at , "#{Position.get(l)} < #{Position.get(r)} , #{l.object_id.to_s(16)}, #{r.object_id.to_s(16)}"
       end
     end
@@ -41,6 +42,7 @@ module Risc
       sorted_objects.shift
       sorted_objects.each_slice(2) do |l,r|
         next unless r
+        next if l.is_a?(Label) or r.is_a?(Label)
         assert Position.get(l).at < Position.get(r).at , "#{Position.get(l)} < #{Position.get(r)} , #{l.object_id.to_s(16)}, #{r.object_id.to_s(16)}"
       end
     end