Revert of Remove more dead code after Object.observe removal

src/js/v8natives.js

Index: src/js/v8natives.js
diff --git a/src/js/v8natives.js b/src/js/v8natives.js
index 44be9419766b49424e1c522af9cb82c7032c4ff7..be7271b1f061dcf61b7b04e815cebc327edd7b58 100644
--- a/src/js/v8natives.js
+++ b/src/js/v8natives.js
@@ -142,6 +142,52 @@
   return %PropertyIsEnumerable(TO_OBJECT(this), P);
 }
 
+
+// Extensions for providing property getters and setters.
+function ObjectDefineGetter(name, fun) {
+  var receiver = this;
+  if (IS_NULL(receiver) || IS_UNDEFINED(receiver)) {
+    receiver = %GlobalProxy(ObjectDefineGetter);
+  }
+  if (!IS_CALLABLE(fun)) {
+    throw MakeTypeError(kObjectGetterExpectingFunction);
+  }
+  var desc = {get: fun, enumerable: true, configurable: true};
+  %reflect_define_property(receiver, name, desc);
+}
+
+
+function ObjectLookupGetter(name) {
+  var receiver = this;
+  if (IS_NULL(receiver) || IS_UNDEFINED(receiver)) {
+    receiver = %GlobalProxy(ObjectLookupGetter);
+  }
+  return %LookupAccessor(TO_OBJECT(receiver), TO_NAME(name), GETTER);
+}
+
+
+function ObjectDefineSetter(name, fun) {
+  var receiver = this;
+  if (IS_NULL(receiver) || IS_UNDEFINED(receiver)) {
+    receiver = %GlobalProxy(ObjectDefineSetter);
+  }
+  if (!IS_CALLABLE(fun)) {
+    throw MakeTypeError(kObjectSetterExpectingFunction);
+  }
+  var desc = {set: fun, enumerable: true, configurable: true};
+  %reflect_define_property(receiver, name, desc);
+}
+
+
+function ObjectLookupSetter(name) {
+  var receiver = this;
+  if (IS_NULL(receiver) || IS_UNDEFINED(receiver)) {
+    receiver = %GlobalProxy(ObjectLookupSetter);
+  }
+  return %LookupAccessor(TO_OBJECT(receiver), TO_NAME(name), SETTER);
+}
+
+
 // ES6 7.3.9
 function GetMethod(obj, p) {
   var func = obj[p];
@@ -150,6 +196,7 @@
   throw MakeTypeError(kCalledNonCallable, typeof func);
 }
 
+
 // ES6 section 19.1.2.18.
 function ObjectSetPrototypeOf(obj, proto) {
   CHECK_OBJECT_COERCIBLE(obj, "Object.setPrototypeOf");
@@ -164,6 +211,7 @@
 
   return obj;
 }
+
 
 // ES6 B.2.2.1.1
 function ObjectGetProto() {
@@ -207,10 +255,10 @@
   "valueOf", ObjectValueOf,
   "isPrototypeOf", ObjectIsPrototypeOf,
   "propertyIsEnumerable", ObjectPropertyIsEnumerable,
-  // __defineGetter__ is added in bootstrapper.cc.
-  // __lookupGetter__ is added in bootstrapper.cc.
-  // __defineSetter__ is added in bootstrapper.cc.
-  // __lookupSetter__ is added in bootstrapper.cc.
+  "__defineGetter__", ObjectDefineGetter,
+  "__lookupGetter__", ObjectLookupGetter,
+  "__defineSetter__", ObjectDefineSetter,
+  "__lookupSetter__", ObjectLookupSetter
 ]);
 utils.InstallGetterSetter(
     GlobalObject.prototype, "__proto__", ObjectGetProto, ObjectSetProto);