Centralize and standardize logic for ExpressionClassifier accumulation

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 7799 matching lines @@
     "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; } };",
 
-    "var f = async(x = await) => 1;",
-
     "function* g() { var f = async yield => 1; }",
     "function* g() { var f = async(yield) => 1; }",
     "function* g() { var f = async(x = yield) => 1; }",
     "function* g() { var f = async({x = yield}) => 1; }",
 
     "class C { async constructor() {} }",
     "class C {}; class C2 extends C { async constructor() {} }",
     "class C { static async prototype() {} }",
     "class C {}; class C2 extends C { static async prototype() {} }",
 
@@ skipping 56 matching lines @@
     "var f = async({ await } = {}) => 1;",
     "var f = async({ await = 1 } = {}) => 1;",
     "var f = async([await]) => 1;",
     "var f = async([await] = []) => 1;",
     "var f = async([await = 1]) => 1;",
     "var f = async([await = 1] = []) => 1;",
     "var f = async(...await) => 1;",
     "var f = async(await) => 1;",
     "var f = async(await = 1) => 1;",
     "var f = async(...[await]) => 1;",
+    "var f = async(x = await) => 1;",
 
     // v8:5190
     "var f = async(1) => 1",
     "var f = async('str') => 1",
     "var f = async(/foo/) => 1",
     "var f = async({ foo = async(1) => 1 }) => 1",
     "var f = async({ foo = async(a) => 1 })",
 
+    "var f = async(x = async(await)) => 1;",
+    "var f = async(x = { [await]: 1 }) => 1;",
+    "var f = async(x = class extends (await) { }) => 1;",
+    "var f = async(x = class { static [await]() {} }) => 1;",
+    "var f = async({ x = await }) => 1;",
+
     NULL
   };
   // clang-format on
 
   static const ParserFlag always_flags[] = {kAllowHarmonyAsyncAwait};
   RunParserSyncTest(context_data, error_data, kError, NULL, 0, always_flags,
                     arraysize(always_flags));
   RunParserSyncTest(strict_context_data, strict_error_data, kError, NULL, 0,
                     always_flags, arraysize(always_flags));
 
@@ skipping 259 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));
 }