Make generators non-constructable.

test/mjsunit/es6/generators-iteration.js

Index: test/mjsunit/es6/generators-iteration.js
diff --git a/test/mjsunit/es6/generators-iteration.js b/test/mjsunit/es6/generators-iteration.js
index faeb68380fea4aa67a97ace057291d075e23a6c8..e61a7c3a9a5c8a44060ab5f380bc347c38291a19 100644
--- a/test/mjsunit/es6/generators-iteration.js
+++ b/test/mjsunit/es6/generators-iteration.js
@@ -101,9 +101,9 @@ function TestGenerator(g, expected_values_for_next,
   testThrow(function*() { return yield* g(); });
 
   if (g instanceof GeneratorFunction) {
-    testNext(function() { return new g(); });
-    testSend(function() { return new g(); });
-    testThrow(function() { return new g(); });
+    testNext(g);
+    testSend(g);
+    testThrow(g);
   }
 }
 
@@ -259,18 +259,6 @@ TestGenerator(
     [1, 2, undefined]);
 
 TestGenerator(
-    function g18() {
-      function* g() { yield this.x; yield this.y; }
-      var iter = new g;
-      iter.x = 1;
-      iter.y = 2;
-      return iter;
-    },
-    [1, 2, undefined],
-    "foo",
-    [1, 2, undefined]);
-
-TestGenerator(
     function* g19() {
       var x = 1;
       yield x;