Remove more dead code after Object.observe removal

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 66e3e413aaecb69372f1f800c5e1f03eb0019a96..9b5a18cfb725390a31bd64f023489fe5a54dfe3b 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1088,8 +1088,20 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     SimpleInstallFunction(object_function, "seal", Builtins::kObjectSeal, 1,
                           false);
 
+    SimpleInstallFunction(isolate->initial_object_prototype(),
+                          "__defineGetter__", Builtins::kObjectDefineGetter, 2,
+                          true);
+    SimpleInstallFunction(isolate->initial_object_prototype(),
+                          "__defineSetter__", Builtins::kObjectDefineSetter, 2,
+                          true);
     SimpleInstallFunction(isolate->initial_object_prototype(), "hasOwnProperty",
                           Builtins::kObjectHasOwnProperty, 1, true);
+    SimpleInstallFunction(isolate->initial_object_prototype(),
+                          "__lookupGetter__", Builtins::kObjectLookupGetter, 1,
+                          true);
+    SimpleInstallFunction(isolate->initial_object_prototype(),
+                          "__lookupSetter__", Builtins::kObjectLookupSetter, 1,
+                          true);
   }
 
   Handle<JSObject> global(native_context()->global_object());