Enable compiling mjsunit tests as ES6 modules

test/cctest/test-modules.cc

-// Copyright 2015 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/cctest.h"
-
-TEST(ModuleCompilation) {
-  v8::internal::FLAG_harmony_modules = true;
-  v8::Isolate* isolate = CcTest::isolate();
-  v8::HandleScope handle_scope(isolate);
-  LocalContext context;
-
-  CompileRun(
-      "var data = [];"
-      "function store(thing) {"
-      "  data.push(thing);"
-      "}");
-
-  CompileRunModule(
-      "export let a = 42;"
-      "store(a)");
-
-  CHECK_EQ(1, CompileRun("data.length")->Int32Value());
-  CHECK_EQ(42, CompileRun("data[0]")->Int32Value());
-}