Rework standalone to use a synchronous loader that does not invoke Dart code

runtime/vm/service_isolate.cc

Index: runtime/vm/service_isolate.cc
diff --git a/runtime/vm/service_isolate.cc b/runtime/vm/service_isolate.cc
index e65c53962fd11854ce8a37c1ac8b8db358be8cd8..f02499c8a989ed08b5d351f354e20d4b8e74fa9d 100644
--- a/runtime/vm/service_isolate.cc
+++ b/runtime/vm/service_isolate.cc
@@ -382,6 +382,10 @@ class RunServiceTask : public ThreadPool::Task {
       if (!error.IsNull() && !error.IsUnwindError()) {
         OS::PrintErr("vm-service: Error: %s\n", error.ToErrorCString());
       }
+      error = I->sticky_error();
+      if (!error.IsNull() && !error.IsUnwindError()) {
+        OS::PrintErr("vm-service: Error: %s\n", error.ToErrorCString());
+      }
       Dart::RunShutdownCallback();
     }
     // Shut the isolate down.