Add a stub for IO#closed?

elia · elia · commit c830a87421b9 · 2015-01-27T00:16:35.000+01:00
diff --git a/opal/corelib/io.rb b/opal/corelib/io.rb
@@ -7,6 +7,10 @@ def tty?
     @tty
   end
 
+  def closed?
+    @closed
+  end
+
   attr_accessor :write_proc
 
   def write(string)
