Iterator functions:

- removed memory leak
- don't close iterator when IteratorStepValue fails
- fixed  Iterator Wrap next() and return() arguments
- fixed Iterator.from()

test262.conf

@@ -304,6 +304,9 @@ test262/test/built-ins/String/prototype/split/cstm-split-on-string-primitive.js
 # spec updates it in this case)
 test262/test/staging/sm/Array/frozen-dense-array.js
 
+# does not match spec
+test262/test/staging/sm/Iterator/from/wrap-next-not-object-throws.js
+
 # not supported
 test262/test/staging/sm/extensions/censor-strict-caller.js
 test262/test/staging/sm/JSON/parse-with-source.js