[parser] don't accept PRIVATE_NAME for object literal property names

Currently, PRIVATE_NAME / PrivateIdentifier is not valid in
ObjectLiterals or other places expecting the PropertyName production.
A SyntaxError here prevents an access violation later on when attempting
to dereference a null property key

BUG=v8:8808
R=gsathya@chromium.org, littledan@chromium.org

Change-Id: Idde9c669cb48c1595b83115351a8fe0caed40eef
Reviewed-on: https://chromium-review.googlesource.com/c/1461161Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#59515}

src/parsing/parser-base.h

@@ -2274,6 +2274,11 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ParsePropertyInfo* prop_info,
   Token::Value name_token = peek();
   Scanner::Location next_loc = scanner()->peek_location();
 
+  if (name_token == Token::PRIVATE_NAME) {
+    ReportUnexpectedToken(Next());
+    return impl()->NullLiteralProperty();
+  }
+
   ExpressionT name_expression = ParseProperty(prop_info);
   IdentifierT name = prop_info->name;
   ParseFunctionFlags function_flags = prop_info->function_flags;

test/cctest/test-parsing.cc

@@ -5620,6 +5620,8 @@ TEST(PrivateMembersInNonClassNoErrors) {
                                    {"function() {", "}"},
                                    {"() => {", "}"},
                                    {"class C { test() {", "} }"},
+                                   {"const {", "} = {}"},
+                                   {"({", "} = {})"},
                                    {nullptr, nullptr}};
   const char* class_body_data[] = {
     "#a = 1",

test/message/fail/destructuring-object-private-name.js

+// Copyright 2019 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.
+
+// Flags: --harmony-class-fields
+
+class Foo {
+  #x = 1;
+  destructureX() {
+    const { #x: x } = this;
+    return x;
+  }
+}

test/message/fail/destructuring-object-private-name.out

+*%(basename)s:10: SyntaxError: Unexpected identifier
+    const { #x: x } = this;
+            ^^
+SyntaxError: Unexpected identifier

test/mjsunit/harmony/regress/regress-8808.js

+// Copyright 2019 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.
+
+// Flags: --harmony-class-fields
+
+assertThrows(() => eval(`
+  class Foo {
+    #x = 1;
+    destructureX() {
+      const { #x: x } = this;
+      return x;
+    }
+  }
+`), SyntaxError);