[modules] Refactor parsing of anonymous declarations in default 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 5492 matching lines @@
       "export function func() { };",
       "export class C { };",
       "export { };",
       "function f() {}; f(); export { f };",
       "var a, b, c; export { a, b as baz, c };",
       "var d, e; export { d as dreary, e, };",
       "export default function f() {}",
       "export default function() {}",
       "export default function*() {}",
       "export default class C {}",
-      "export default class {}"
-      "export default class extends C {}"
+      "export default class {}",
+      "export default class extends C {}",
       "export default 42",
       "var x; export default x = 7",
       "export { Q } from 'somemodule.js';",
       "export * from 'somemodule.js';",
       "var foo; export { foo as for };",
       "export { arguments } from 'm.js';",
       "export { for } from 'm.js';",
       "export { yield } from 'm.js'",
       "export { static } from 'm.js'",
       "export { let } from 'm.js'",
@@ skipping 2415 matching lines @@
     "(a,);",
     "(a,b,c,);",
     NULL
   };
   // clang-format on
 
   static const ParserFlag always_flags[] = {kAllowHarmonyTrailingCommas};
   RunParserSyncTest(context_data, data, kError, NULL, 0, always_flags,
                     arraysize(always_flags));
 }