Fix to emit heredoc reminders on rescue postcontrol

[Fix #195]

lib/unparser/generation.rb

@@ -204,7 +204,9 @@ def emit_body_ensure_rescue(node)
     end
 
     def emit_rescue_postcontrol(node)
-      writer_with(Writer::Rescue, node).emit_postcontrol
+      writer = writer_with(Writer::Rescue, node)
+      writer.emit_postcontrol
+      writer.emit_heredoc_reminders
     end
 
     def emit_rescue_regular(node)

lib/unparser/writer/rescue.rb

@@ -20,6 +20,10 @@ def emit_regular
         end
       end
 
+      def emit_heredoc_reminders
+        emitter(body).emit_heredoc_reminders
+      end
+
       def emit_postcontrol
         visit(body)
         writer_with(Resbody, rescue_body).emit_postcontrol

test/corpus/literal/dstr.rb

@@ -17,6 +17,10 @@
   #{}
   #{}
 HEREDOC
+<<-HEREDOC rescue nil
+#{}
+a
+HEREDOC
 "a#$1"
 "a#$a"
 "a#@a"