[snapshot] Move builtins generation into mksnapshot

test/cctest/setup-builtins-for-tests.cc

Index: test/cctest/setup-builtins-for-tests.cc
diff --git a/test/cctest/setup-builtins-for-tests.cc b/test/cctest/setup-builtins-for-tests.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b378275f5f94c0f4960f68c4629b2eed956de43b
--- /dev/null
+++ b/test/cctest/setup-builtins-for-tests.cc
@@ -0,0 +1,18 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "test/cctest/setup-builtins-for-tests.h"
+
+namespace v8 {
+namespace internal {
+
+void SetupBuiltinsDelegateForTests::SetupBuiltins(Isolate* isolate,
+                                                  bool create_heap_objects) {
+  if (create_heap_objects) {
+    SetupBuiltinsInternal(isolate);
+  }
+}
+
+}  // namespace internal
+}  // namespace v8