Merge V8 at 3.9.24.13

Bug: 5688872
Change-Id: Id0aa8d23375030494d3189c31774059c0f5398fc
diff --git a/test/mjsunit/mjsunit.js b/test/mjsunit/mjsunit.js
index faa5a43..033c78f 100644
--- a/test/mjsunit/mjsunit.js
+++ b/test/mjsunit/mjsunit.js
@@ -221,9 +221,11 @@
 
 
   assertSame = function assertSame(expected, found, name_opt) {
+    // TODO(mstarzinger): We should think about using Harmony's egal operator
+    // or the function equivalent Object.is() here.
     if (found === expected) {
       if (expected !== 0 || (1 / expected) == (1 / found)) return;
-    } else if (isNaN(expected) && isNaN(found)) {
+    } else if ((expected !== expected) && (found !== found)) {
       return;
     }
     fail(PrettyPrint(expected), found, name_opt);