Disallow 'await' in object literal shorthand position

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 7842 matching lines @@
     "var O = { async 0(a, a) {} }",
 
     "async function f() { var O = { async [await](a, a) {} } }",
 
     "var asyncFn = async function() { await; }",
     "async function f() { await; }",
     "var O = { async method() { await; } };",
     "var f = async() => await;",
     "var f = async() => { await; };",
 
+    "async function f() { return {await} }",
+
     "var asyncFn = async function*() {}",
     "async function* f() {}",
     "var O = { *async method() {} };",
     "var O = { async *method() {} };",
     "var O = { async method*() {} };",
 
     "var asyncFn = async function(x = await 1) { return x; }",
     "async function f(x = await 1) { return x; }",
     "var f = async(x = await 1) => x;",
     "var O = { async method(x = await 1) { return x; } };",
@@ skipping 314 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));
 }