Migrated several tests from blink to V8 repository.

test/webkit/dfg-weak-js-constant-silent-fill.js

Index: test/webkit/dfg-weak-js-constant-silent-fill.js
diff --git a/test/webkit/concat-while-having-a-bad-time.js b/test/webkit/dfg-weak-js-constant-silent-fill.js
similarity index 67%
copy from test/webkit/concat-while-having-a-bad-time.js
copy to test/webkit/dfg-weak-js-constant-silent-fill.js
index dfda1e08a0b36194b787a44ee12a9693acd8aeaf..fa06a905bc4050bcb205a80e90908a4e1738ae92 100644
--- a/test/webkit/concat-while-having-a-bad-time.js
+++ b/test/webkit/dfg-weak-js-constant-silent-fill.js
@@ -22,10 +22,27 @@
 // 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."
+"Tests that DFG silent spill and fill of WeakJSConstants does not result in nonsense."
 );
 
-Object.defineProperty(Array.prototype, 0, { writable: false });
-shouldBe("[42].concat()", "[42]");
+function foo(a, b, c, d)
+{
+    a.f = 42; // WeakJSConstants corresponding to the o.f transition get created here.
+    var x = !d; // Silent spilling and filling happens here.
+    b.f = x; // The WeakJSConstants get reused here.
+    var y = !d; // Silent spilling and filling happens here.
+    c.f = y; // The WeakJSConstants get reused here.
+}
 
+var Empty = "";
+
+for (var i = 0; i < 1000; ++i) {
+    var o1 = new Object();
+    var o2 = new Object();
+    var o3 = new Object();
+    eval(Empty + "foo(o1, o2, o3, \"stuff\")");
+    shouldBe("o1.f", "42");
+    shouldBe("o2.f", "false");
+    shouldBe("o3.f", "false");
+}