Make --trace-loading great again.

runtime/bin/gen_snapshot.cc

Index: runtime/bin/gen_snapshot.cc
diff --git a/runtime/bin/gen_snapshot.cc b/runtime/bin/gen_snapshot.cc
index bbf25a4458c138e317242cb4792c170ebe4b33f1..d345a1d51cafcaa9093c593157c6d2b233505e04 100644
--- a/runtime/bin/gen_snapshot.cc
+++ b/runtime/bin/gen_snapshot.cc
@@ -1428,7 +1428,8 @@ static Dart_Isolate CreateServiceIsolate(const char* script_uri,
   ASSERT(Dart_IsServiceIsolate(isolate));
   // Load embedder specific bits and return. Will not start http server.
   if (!VmService::Setup("127.0.0.1", -1, false /* running_precompiled */,
-                        false /* server dev mode */)) {
+                        false /* server dev mode */,
+                        false /* trace_loading */)) {
     *error = strdup(VmService::GetErrorMessage());
     return NULL;
   }