Introduce JSFunction::EnsureHasInitialMap method.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 4927cac376176dbea65ca4ed45c2d893ee0b8d02..fb14663341c604a7ba546a4cd5a3b91904546386 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -580,6 +580,12 @@ Handle<JSObject> Factory::NewFunctionPrototype(Handle<JSFunction> function) {
 }
 
 
+Handle<Map> Factory::NewInitialMap(Handle<JSFunction> function) {
+  CALL_HEAP_FUNCTION(
+      isolate(), isolate()->heap()->AllocateInitialMap(*function), Map);
+}
+
+
 Handle<Map> Factory::CopyWithPreallocatedFieldDescriptors(Handle<Map> src) {
   CALL_HEAP_FUNCTION(
       isolate(), src->CopyWithPreallocatedFieldDescriptors(), Map);
@@ -1045,6 +1051,7 @@ Handle<String> Factory::InternalizedStringFromString(Handle<String> value) {
 
 Handle<JSObject> Factory::NewJSObject(Handle<JSFunction> constructor,
                                       PretenureFlag pretenure) {
+  JSFunction::EnsureHasInitialMap(constructor);
   CALL_HEAP_FUNCTION(
       isolate(),
       isolate()->heap()->AllocateJSObject(*constructor, pretenure), JSObject);
@@ -1191,6 +1198,19 @@ void Factory::SetContent(Handle<JSArray> array,
 }
 
 
+Handle<JSGeneratorObject> Factory::NewJSGeneratorObject(
+    Handle<JSFunction> function) {
+  ASSERT(function->shared()->is_generator());
+  JSFunction::EnsureHasInitialMap(function);
+  Handle<Map> map(function->initial_map());
+  ASSERT(map->instance_type() == JS_GENERATOR_OBJECT_TYPE);
+  CALL_HEAP_FUNCTION(
+      isolate(),
+      isolate()->heap()->AllocateJSObjectFromMap(*map),
+      JSGeneratorObject);
+}
+
+
 Handle<JSArrayBuffer> Factory::NewJSArrayBuffer() {
   Handle<JSFunction> array_buffer_fun(
       isolate()->context()->native_context()->array_buffer_fun());