[es6] Implement for-of iterator finalization

test/mjsunit/strong/for-in.js

Index: test/mjsunit/strong/for-in.js
diff --git a/test/mjsunit/strong/for-in.js b/test/mjsunit/strong/for-in.js
index 8fa901020263d687ef993de35647e73ca039ee32..641248c408e73412aca464f1fe6de1622e9b3e29 100644
--- a/test/mjsunit/strong/for-in.js
+++ b/test/mjsunit/strong/for-in.js
@@ -9,9 +9,3 @@
   assertThrows("'use strong'; for (let x in []) {}", SyntaxError);
   assertThrows("'use strong'; for (const x in []) {}", SyntaxError);
 })();
-
-(function ForOfStatement() {
-  assertTrue(eval("'use strong'; for (x of []) {} true"));
-  assertTrue(eval("'use strong'; for (let x of []) {} true"));
-  assertTrue(eval("'use strong'; for (const x of []) {} true"));
-})();