Implement closurization of regular methods in ObjectMirror.getField in the VM.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 9e2fa47592f6324cc08e9ed1f5ae672c91e1fc6c..3d06df2278a2a6ae290817d2d91c0804c74117b0 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -4928,6 +4928,18 @@ void Function::BuildSignatureParameters(
 }
 
 
+RawInstance* Function::ImplicitStaticClosure() const {
+  if (implicit_static_closure() == Instance::null()) {
+    ObjectStore* object_store = Isolate::Current()->object_store();
+    const Context& context = Context::Handle(object_store->empty_context());
+    const Instance& closure =
+        Instance::Handle(Closure::New(*this, context, Heap::kOld));
+    set_implicit_static_closure(closure);
+  }
+  return implicit_static_closure();
+}
+
+
 RawString* Function::BuildSignature(
     bool instantiate,
     NameVisibility name_visibility,