Implement spawnUri from dart:isolate. This function allows us to

runtime/vm/benchmark_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/benchmark_test.h"
 
 #include "bin/file.h"
 
 #include "platform/assert.h"
 
@@ skipping 38 matching lines @@
 #endif  // TARGET_ARCH_IA32 || TARGET_ARCH_X64
 
 
 //
 // Measure creation of core isolate from a snapshot.
 //
 BENCHMARK(CorelibIsolateStartup) {
   const int kNumIterations = 100;
   char* err = NULL;
   Dart_Isolate base_isolate = Dart_CurrentIsolate();
-  Dart_Isolate test_isolate = Dart_CreateIsolate(NULL, NULL, NULL, &err);
+  Dart_Isolate test_isolate = Dart_CreateIsolate(NULL, NULL, NULL, NULL, &err);
   EXPECT(test_isolate != NULL);
   Dart_EnterScope();
   uint8_t* buffer = NULL;
   intptr_t size = 0;
   Dart_Handle result = Dart_CreateSnapshot(&buffer, &size);
   EXPECT(!Dart_IsError(result));
   Timer timer(true, "Core Isolate startup benchmark");
   timer.Start();
   for (int i = 0; i < kNumIterations; i++) {
-    Dart_Isolate new_isolate = Dart_CreateIsolate(NULL, buffer, NULL, &err);
+    Dart_Isolate new_isolate =
+        Dart_CreateIsolate(NULL, NULL, buffer, NULL, &err);
     EXPECT(new_isolate != NULL);
     Dart_ShutdownIsolate();
   }
   timer.Stop();
   int64_t elapsed_time = timer.TotalElapsedTime();
   benchmark->set_score(elapsed_time / kNumIterations);
   Dart_EnterIsolate(test_isolate);
   Dart_ExitScope();
   Dart_ShutdownIsolate();
   Dart_EnterIsolate(base_isolate);
@@ skipping 255 matching lines @@
       reinterpret_cast<Dart_NativeEntryResolver>(StackFrameNativeResolver));
   Dart_Handle cls = Dart_GetClass(lib, Dart_NewString("StackFrameTest"));
   Dart_Handle result = Dart_Invoke(cls, Dart_NewString("testMain"), 0, NULL);
   EXPECT_VALID(result);
   int64_t elapsed_time = 0;
   EXPECT(!Dart_IsError(Dart_IntegerToInt64(result, &elapsed_time)));
   benchmark->set_score(elapsed_time);
 }
 
 }  // namespace dart