Create test isolates using a snapshot, this ensures that we do not depend

runtime/vm/dart_api_impl_test.cc

Index: runtime/vm/dart_api_impl_test.cc
===================================================================
--- runtime/vm/dart_api_impl_test.cc	(revision 23022)
+++ runtime/vm/dart_api_impl_test.cc	(working copy)
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
+#include "bin/builtin.h"
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "platform/utils.h"
@@ -6005,6 +6006,9 @@
   "}\n"
   ;  // NOLINT
 
+  bin::Builtin::SetNativeResolver(bin::Builtin::kBuiltinLibrary);
+  bin::Builtin::SetNativeResolver(bin::Builtin::kIOLibrary);
+
   Dart_Handle result = Dart_SetLibraryTagHandler(library_handler);
   EXPECT_VALID(result);