Upgrade V8 to 5.1.281.57

Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
diff --git a/test/webkit/fast/js/parser-syntax-check.js b/test/webkit/fast/js/parser-syntax-check.js
index a3fef13..c003745 100644
--- a/test/webkit/fast/js/parser-syntax-check.js
+++ b/test/webkit/fast/js/parser-syntax-check.js
@@ -21,6 +21,8 @@
 // (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: --no-harmony-restrictive-declarations
+
 description(
 "This test checks that the following expressions or statements are valid ECMASCRIPT code or should throw parse error"
 );