Upgrade V8 to 5.1.281.57  DO NOT MERGE

FPIIM-449

Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
(cherry picked from commit 3b9bc31999c9787eb726ecdbfd5796bfdec32a18)
diff --git a/test/mjsunit/harmony/regexp-property-disabled.js b/test/mjsunit/harmony/regexp-property-disabled.js
new file mode 100644
index 0000000..7a3158c
--- /dev/null
+++ b/test/mjsunit/harmony/regexp-property-disabled.js
@@ -0,0 +1,18 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-unicode-regexps --no-harmony-regexp-property
+
+function test(source, message) {
+  try {
+    eval(source);
+  } catch (e) {
+    assertEquals(message, e.message);
+    return;
+  }
+  assertUnreachable();
+}
+
+test("/\\pL/u", "Invalid regular expression: /\\pL/: Invalid escape");
+test("/[\\p{L}]/u", "Invalid regular expression: /[\\p{L}]/: Invalid escape");