Roll V8 back to 3.6

Roll back to V8 3.6 to fix x86 build, we don't have ucontext.h.

This reverts commits:
5d4cdbf7a67d3662fa0bee4efdb7edd8daec9b0b
c7cc028aaeedbbfa11c11d0b7b243b3d9e837ed9
592a9fc1d8ea420377a2e7efd0600e20b058be2b

Bug: 5688872
Change-Id: Ic961bb5e65b778e98bbfb71cce71d99fa949e995
diff --git a/test/mjsunit/mjsunit.js b/test/mjsunit/mjsunit.js
index 033c78f..faa5a43 100644
--- a/test/mjsunit/mjsunit.js
+++ b/test/mjsunit/mjsunit.js
@@ -221,11 +221,9 @@
 
 
   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 ((expected !== expected) && (found !== found)) {
+    } else if (isNaN(expected) && isNaN(found)) {
       return;
     }
     fail(PrettyPrint(expected), found, name_opt);