[snapshot] Move builtins generation into mksnapshot

test/cctest/test-serialize.cc

Index: test/cctest/test-serialize.cc
diff --git a/test/cctest/test-serialize.cc b/test/cctest/test-serialize.cc
index 19081691ce3316a4d0d360fc4fb51c8f5647d76d..5039f8881bb61266c0c6ba2db6e4cb99c712e1bd 100644
--- a/test/cctest/test-serialize.cc
+++ b/test/cctest/test-serialize.cc
@@ -49,6 +49,7 @@
 #include "src/snapshot/startup-serializer.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/heap/heap-utils.h"
+#include "test/cctest/setup-builtins-for-tests.h"
 
 using namespace v8::internal;
 
@@ -64,6 +65,7 @@ class TestIsolate : public Isolate {
  public:
   static v8::Isolate* NewInitialized(bool enable_serializer) {
     i::Isolate* isolate = new TestIsolate(enable_serializer);
+    isolate->setup_builtins_delegate_ = new SetupBuiltinsDelegateForTests();
     v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
     v8::Isolate::Scope isolate_scope(v8_isolate);
     isolate->Init(NULL);