Implement ES6 Array.of()

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 893e31be5cd740e8d28192a4799c9cd59d614bf5..69269c78f31fcdd9ca40022333691afca77b246c 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -7804,6 +7804,18 @@ RUNTIME_FUNCTION(Runtime_MathPowRT) {
 }
 
 
+RUNTIME_FUNCTION(Runtime_IsConstructor) {

[rossberg, 2014/07/08 08:39:17]

Drive-by-comment: Unfortunately, I don't think this function is quite correct.
For example, it does not handle function proxies.

[rossberg, 2014/07/08 09:59:09]

And more importantly, for JSFunctions it is testing whether they _have_ a
constructor, not whether they _are_ one -- completely different thing
(GetConstructor will normally return Function.prototype in this case).

So, this whole function is completely wrong. Unfortunately, it's not so simple
to implement it correctly either. You can have a look at Runtime_NewObjectHelper
in runtime.cc to get an idea. But if we actually need such a predicate, then the
condition used there should be properly refactored. For now, I would prefer just
to fall back to IS_SPEC_FUNCTION.

+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+
+  CONVERT_ARG_CHECKED(JSFunction, obj, 0);
+  if (!obj->IsObject()) return isolate->heap()->false_value();
+  bool hasConstructor = !!obj->GetConstructor();
+  return hasConstructor ? isolate->heap()->true_value()
+                        : isolate->heap()->false_value();
+}
+
+
 RUNTIME_FUNCTION(Runtime_RoundNumber) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);