Make it possible to share the embedder's dart sources for the vmservice

runtime/bin/vmservice_impl.cc

Index: runtime/bin/vmservice_impl.cc
diff --git a/runtime/bin/vmservice_impl.cc b/runtime/bin/vmservice_impl.cc
index 0c0a63c047dcc72f602111720d0b07e9905fa0c3..836295c11cd9943712e2ff7334a0060f7aec91ca 100644
--- a/runtime/bin/vmservice_impl.cc
+++ b/runtime/bin/vmservice_impl.cc
@@ -115,6 +115,11 @@ void NotifyServerState(Dart_NativeArguments args) {
   Dart_ExitScope();
 }
 
+
+static void Shutdown(Dart_NativeArguments args) {
+  // NO-OP.
+}
+
 struct VmServiceIONativeEntry {
   const char* name;
   int num_arguments;
@@ -124,6 +129,7 @@ struct VmServiceIONativeEntry {
 
 static VmServiceIONativeEntry _VmServiceIONativeEntries[] = {
   {"VMServiceIO_NotifyServerState", 2, NotifyServerState},
+  {"VMServiceIO_Shutdown", 0, Shutdown },
 };