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 fb89452bdba66b97a4c8d457656917a24014e9b8..7077241630fcd32680a982264fda94ab517ff326 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1576,6 +1576,11 @@ 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);
   }