[parser] Don't resolve preparser variables for arrow functions

I moved AnalyzePartially from ParseFunctionLiteral to SkipFunction, but arrow
functions only used the ResetAfterPreparsing part.

Bug: chromium:888825

Change-Id: I08de99af128b28031df6ed86a725e4dc918078f8
Reviewed-on: https://chromium-review.googlesource.com/1243383Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56218}

src/ast/scopes.cc

@@ -1534,10 +1534,11 @@ void DeclarationScope::SavePreParsedScopeDataForDeclarationScope() {
 void DeclarationScope::AnalyzePartially(AstNodeFactory* ast_node_factory) {
   DCHECK(!force_eager_compilation_);
   ThreadedList<VariableProxy> new_unresolved_list;
-  if (!outer_scope_->is_script_scope() ||
-      (FLAG_preparser_scope_analysis &&
-       preparsed_scope_data_builder_ != nullptr &&
-       preparsed_scope_data_builder_->ContainsInnerFunctions())) {
+  if (!IsArrowFunction(function_kind_) &&
+      (!outer_scope_->is_script_scope() ||
+       (FLAG_preparser_scope_analysis &&
+        preparsed_scope_data_builder_ != nullptr &&
+        preparsed_scope_data_builder_->ContainsInnerFunctions()))) {
     // Try to resolve unresolved variables for this Scope and migrate those
     // which cannot be resolved inside. It doesn't make sense to try to resolve
     // them in the outer Scopes here, because they are incomplete.

src/parsing/parser-base.h

@@ -4398,8 +4398,6 @@ ParserBase<Impl>::ParseArrowFunctionLiteral(
         DCHECK(parse_result);
         USE(parse_result);
         DCHECK_NULL(produced_preparsed_scope_data);
-        formal_parameters.scope->ResetAfterPreparsing(ast_value_factory_,
-                                                      false);
         // Discard any queued destructuring assignments which appeared
         // in this function's parameter list, and which were adopted
         // into this function state, above.

test/mjsunit/regress/regress-crbug-888825.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.
+
+eval("((a=function g() { function g() {}}) => {})();");