[builtins] Properly optimize Object.prototype.isPrototypeOf.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index aff965cae3ce24ece6b206eb28e9e425b676987b..886435ade613293594869cbdec46014d37f84f67 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4580,6 +4580,7 @@ class ContextExtension : public Struct {
   V(Object, assign, ObjectAssign)                           \
   V(Object, create, ObjectCreate)                           \
   V(Object.prototype, hasOwnProperty, ObjectHasOwnProperty) \
+  V(Object.prototype, isPrototypeOf, ObjectIsPrototypeOf)   \
   V(Object.prototype, toString, ObjectToString)             \
   V(RegExp.prototype, compile, RegExpCompile)               \
   V(RegExp.prototype, exec, RegExpExec)                     \