[turbofan] Implement the implicit ToObject for property access.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 40e06c24ce43d5bffff4aa56429cdd5fc5e95ce6..40651f373432508f539f095cd6d7d8897b24cb83 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -1679,6 +1679,20 @@ void JSObject::PrintElementsTransition(
 }
 
 
+// static
+MaybeHandle<JSFunction> Map::GetConstructorFunction(
+    Handle<Map> map, Handle<Context> native_context) {
+  if (map->IsPrimitiveMap()) {
+    int const constructor_function_index = map->GetConstructorFunctionIndex();
+    if (constructor_function_index != kNoConstructorFunctionIndex) {
+      return handle(
+          JSFunction::cast(native_context->get(constructor_function_index)));
+    }
+  }
+  return MaybeHandle<JSFunction>();
+}
+
+
 void Map::PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
                                PropertyAttributes attributes) {
   OFStream os(file);