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/debug-script.js b/test/mjsunit/debug-script.js
index 5ffada1..07f0e3c 100644
--- a/test/mjsunit/debug-script.js
+++ b/test/mjsunit/debug-script.js
@@ -26,6 +26,13 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --expose-debug-as debug --expose-gc --send-idle-notification
+// Flags: --allow-natives-syntax
+// Flags: --noharmony-shipping
+// Note: this test checks that that the number of scripts reported as native
+// by Debug.scripts() is the same as a number of core native scripts.
+// Native scripts that are added by --harmony-shipping are classified
+// as 'experimental', but are still returned by Debug.scripts(), so
+// we disable harmony-shipping for this test
 
 // Get the Debug object exposed from the debug context global object.
 Debug = debug.Debug;
@@ -59,7 +66,7 @@
 }
 
 // This has to be updated if the number of native scripts change.
-assertTrue(named_native_count == 26 || named_native_count == 27);
+assertEquals(%NativeScriptsCount(), named_native_count);
 // Only the 'gc' extension is loaded.
 assertEquals(1, extension_count);
 // This script and mjsunit.js has been loaded.  If using d8, d8 loads