Strip Interface class of most of its logic, make it all about Module exports

test/cctest/test-parsing.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5192 matching lines @@
       "export default let x = 7;",
       "export default const x = 7;",
       "export *;",
       "export * from;",
       "export { Q } from;",
       "export default from 'module.js';",
       "export { for }",
       "export { for as foo }",
       "export { arguments }",
       "export { arguments as foo }",
+      "var a; export { a, a };",
 
       "import from;",
       "import from 'm.js';",
       "import { };",
       "import {;",
       "import };",
       "import { , };",
       "import { , } from 'm.js';",
       "import { a } from;",
       "import { a } 'm.js';",
@@ skipping 317 matching lines @@
   static const ParserFlag always_flags[] = {
       kAllowStrongMode, kAllowHarmonyScoping
   };
   RunParserSyncTest(sloppy_context_data, data, kSuccess, NULL, 0, always_flags,
                     arraysize(always_flags));
   RunParserSyncTest(strict_context_data, data, kSuccess, NULL, 0, always_flags,
                     arraysize(always_flags));
   RunParserSyncTest(strong_context_data, data, kError, NULL, 0, always_flags,
                     arraysize(always_flags));
 }