Update V8 to version 4.1.0.21

This is a cherry-pick of all commits up to and including the
4.1.0.21 cherry-pick in Chromium.

Original commit message:

Version 4.1.0.21 (cherry-pick)

Merged 206e9136bde0f2b5ae8cb77afbb1e7833e5bd412

Unlink pages from the space page list after evacuation.

BUG=430201
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/953813002

Cr-Commit-Position: refs/branch-heads/4.1@{#22}
Cr-Branched-From: 2e08d2a7aa9d65d269d8c57aba82eb38a8cb0a18-refs/heads/candidates@{#25353}

---

FPIIM-449

Change-Id: I8c23c7bbb70772b4858fe8a47b64fa97ee0d1f8c
diff --git a/test/mjsunit/es6/promises.js b/test/mjsunit/es6/promises.js
index faf154e..04059aa 100644
--- a/test/mjsunit/es6/promises.js
+++ b/test/mjsunit/es6/promises.js
@@ -25,13 +25,21 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --allow-natives-syntax
+// Flags: --allow-natives-syntax --harmony-tostring
 
 // Make sure we don't rely on functions patchable by monkeys.
 var call = Function.prototype.call.call.bind(Function.prototype.call)
 var observe = Object.observe;
-var getOwnPropertyNames = Object.getOwnPropertyNames
-var defineProperty = Object.defineProperty
+var getOwnPropertyNames = Object.getOwnPropertyNames;
+var defineProperty = Object.defineProperty;
+
+
+(function() {
+  // Test before clearing global (fails otherwise)
+  assertEquals("[object Promise]",
+      Object.prototype.toString.call(new Promise(function() {})));
+})();
+
 
 function clear(o) {
   if (o === null || (typeof o !== 'object' && typeof o !== 'function')) return