Destructuring parameters with defaults. function x({ foo, bar } = {}) { }

lib/output.js

@@ -639,6 +639,12 @@ function OutputStream(options) {
             name.print(output);
         })
         output.print(self.is_array ? "]" : "}");
+        if (self.default) {
+            output.space();
+            output.print('=');
+            output.space();
+            self.default.print(output)
+        }
     })
 
     DEFPRINT(AST_Debugger, function(self, output){