[es6] Rebaseline tests of 'instanceof' error messages.

test/webkit/instance-of-immediates.js

Index: test/webkit/instance-of-immediates.js
diff --git a/test/webkit/instance-of-immediates.js b/test/webkit/instance-of-immediates.js
index 649a29f5a44d7e317665da46e6c628747692e2ca..be63e4b00b44f4733a42c2cd998f3d0285f0dae0 100644
--- a/test/webkit/instance-of-immediates.js
+++ b/test/webkit/instance-of-immediates.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: --harmony-instanceof
+
 description('This test makes sure that instance of behaves correctly when the value, constructor, or its prototype are immediates.');
 
 // A Constructor to use check for instances of, and an instance called obj.