[parser] Fix aborting preparsing of a function with a rest param.

BUG=chromium:813630

Change-Id: I9eeaeb8830533c178c8073f48f036f9af8887a55
Reviewed-on: https://chromium-review.googlesource.com/972901Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52095}

src/ast/scopes.cc

@@ -1492,6 +1492,7 @@ void DeclarationScope::ResetAfterPreparsing(AstValueFactory* ast_value_factory,
   unresolved_ = nullptr;
   sloppy_block_function_map_ = nullptr;
   rare_data_ = nullptr;
+  has_rest_ = false;
 
   if (aborted) {
     // Prepare scope for use in the outer zone.

test/mjsunit/regress/regress-crbug-813630.js

+// Copyright 2018 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.
+
+// Regression test for a bug where aborting a function which has a rest
+// parameter didn't work correctly.
+function g(...args) {
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+  x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;x;
+}