Allocate block-scoped global bindings to global context.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 76bfc9b459923d5f0369ebad873713e1167afb92..84d23e4315a8d29008515aae81525d60cdb06f0a 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1330,6 +1330,12 @@ Handle<Context> Isolate::native_context() {
 }
 
 
+Handle<Context> Isolate::global_context() {
+  GlobalObject* global = thread_local_top()->context_->global_object();
+  return Handle<Context>(global->global_context());
+}
+
+
 Handle<Context> Isolate::GetCallingNativeContext() {
   JavaScriptFrameIterator it;
 #ifdef ENABLE_DEBUGGER_SUPPORT