- Properly load the core libraries as libraries and not as scripts.

runtime/vm/bootstrap.cc

Index: runtime/vm/bootstrap.cc
===================================================================
--- runtime/vm/bootstrap.cc	(revision 18894)
+++ runtime/vm/bootstrap.cc	(working copy)
@@ -22,11 +22,11 @@
                                  bool patch) {
   return Script::New(String::Handle(String::New(url, Heap::kOld)),
                      String::Handle(String::New(source, Heap::kOld)),
-                     patch ? RawScript::kPatchTag : RawScript::kSourceTag);
+                     patch ? RawScript::kPatchTag : RawScript::kLibraryTag);
 }
 
 
-RawScript* Bootstrap::LoadASyncScript(bool patch) {
+RawScript* Bootstrap::LoadAsyncScript(bool patch) {
   const char* url = patch ? "dart:async-patch" : "dart:async";
   const char* source = patch ? async_patch_ : async_source_;
   return LoadScript(url, source, patch);