Array.observe emit splices for array length change and update index >= length

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 85812ca28cc8679cd9a9504967dc4405554f1dfa..845f38dda0be9b4311313e8dfe76b9000de6dc71 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1570,6 +1570,11 @@ void Genesis::InstallExperimentalNativeFunctions() {
   }
   if (FLAG_harmony_observation) {
     INSTALL_NATIVE(JSFunction, "NotifyChange", observers_notify_change);
+    INSTALL_NATIVE(JSFunction, "EnqueueSpliceRecord", observers_enqueue_splice);
+    INSTALL_NATIVE(JSFunction, "BeginPerformSplice",
+                   observers_begin_perform_splice);
+    INSTALL_NATIVE(JSFunction, "EndPerformSplice",
+                   observers_end_perform_splice);
     INSTALL_NATIVE(JSFunction, "DeliverChangeRecords",
                    observers_deliver_changes);
   }