Make "length" and "BYTES_PER_ELEMENT" properties of typed arrays accessible.

samples/shell.cc

Index: samples/shell.cc
diff --git a/samples/shell.cc b/samples/shell.cc
index 72aca0ff563ca865c37fc4d21c9486fecfab487d..222eeda1149406eea9206e54746fbd498a41829f 100644
--- a/samples/shell.cc
+++ b/samples/shell.cc
@@ -466,6 +466,10 @@ v8::Handle<v8::Value> CreateExternalArray(const v8::Arguments& args,
       v8::Persistent<v8::Object>::New(array);
   persistent_array.MakeWeak(data, ExternalArrayWeakCallback);
   array->SetIndexedPropertiesToExternalArrayData(data, type, length);
+  array->Set(v8::String::New("length"), v8::Int32::New(length),
+             v8::ReadOnly);
+  array->Set(v8::String::New("BYTES_PER_ELEMENT"),
+             v8::Int32::New(element_size));
   return array;
 }