Ensure IteratorClose is called for errors in non-declaring assignments

test/mjsunit/harmony/iterator-close.js

Index: test/mjsunit/harmony/iterator-close.js
diff --git a/test/mjsunit/harmony/iterator-close.js b/test/mjsunit/harmony/iterator-close.js
index 3cc4412e8a967c3c18015af989ecb5ef14bd2e18..d3b7dc91684dad9a2ea0e2697b17c8dd6b2fb981 100644
--- a/test/mjsunit/harmony/iterator-close.js
+++ b/test/mjsunit/harmony/iterator-close.js
@@ -155,6 +155,13 @@ function* g() { yield 42; return 88 };
   log = [];
   assertEquals(42, eval('for (x of g()) { x; }'));
   assertEquals([], log);
+
+  // Even if doing the assignment throws, still call return
+  x = { set attr(_) { throw 1234; } };
+  assertThrowsEquals(() => {
+    for (x.attr of g()) { throw 456; }
+  }, 1234);
+  assertEquals([[]], log);
 }