Migrated several tests from blink to V8 repository.

test/webkit/for-in-avoid-duplicates.js

Index: test/webkit/for-in-avoid-duplicates.js
diff --git a/test/webkit/concat-while-having-a-bad-time.js b/test/webkit/for-in-avoid-duplicates.js
similarity index 81%
copy from test/webkit/concat-while-having-a-bad-time.js
copy to test/webkit/for-in-avoid-duplicates.js
index dfda1e08a0b36194b787a44ee12a9693acd8aeaf..a961f910eba3afd9f896184f3329fbec467d7572 100644
--- a/test/webkit/concat-while-having-a-bad-time.js
+++ b/test/webkit/for-in-avoid-duplicates.js
@@ -22,10 +22,22 @@
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 description(
-"Tests the behavior of Array.prototype.concat while the array is having a bad time due to one of the elements we are concatenating."
+"This tests that for/in statements don't report properties that are in both an object and its prototype more than once."
 );
 
-Object.defineProperty(Array.prototype, 0, { writable: false });
-shouldBe("[42].concat()", "[42]");
 
+function constr() {
+    this.xxx = "foo";
+    this.yyy = "bar";
+}
 
+constr.prototype = { xxx: "baz", yyy: "quux" };
+
+var obj = new constr();
+
+var i = 0;
+for (var prop in obj) {
+    ++i;
+}
+
+shouldBe("i", "2");