1. Dynamic compute the main closure that needs to be run by the main isolate

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index c6715d6f58a6b5115d9d5ac45eef6cad6bc208bf..d5062633402b9c66a7b4e20c46a5eb4e109c01be 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -3983,6 +3983,11 @@ class Library : public Object {
   void CheckReload(const Library& replacement,
                    IsolateReloadContext* context) const;
 
+  // Returns a closure of top level function 'name' in the exported namespace
+  // of this library. If a top level function 'name' does not exist we look
+  // for a top level getter 'name' that returns a closure.
+  RawObject* GetFunctionClosure(const String& name) const;
+
  private:
   static const int kInitialImportsCapacity = 4;
   static const int kImportsCapacityIncrement = 8;