Use Scope::function_kind_ to distinguish arrow function scopes

src/preparser.h

 // Copyright 2012 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.
 
 #ifndef V8_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/bailout-reason.h"
 #include "src/expression-classifier.h"
 #include "src/func-name-inferrer.h"
@@ skipping 289 matching lines @@
     ~ParsingModeScope() {
       parser_->mode_ = old_mode_;
     }
 
    private:
     ParserBase* parser_;
     Mode old_mode_;
   };
 
   Scope* NewScope(Scope* parent, ScopeType scope_type) {
-    // Must always pass the function kind for FUNCTION_SCOPE and ARROW_SCOPE.
+    // Must always pass the function kind for FUNCTION_SCOPE.
     DCHECK(scope_type != FUNCTION_SCOPE);
-    DCHECK(scope_type != ARROW_SCOPE);
     return NewScope(parent, scope_type, kNormalFunction);
   }
 
   Scope* NewScope(Scope* parent, ScopeType scope_type, FunctionKind kind) {
     DCHECK(ast_value_factory());
     DCHECK(scope_type != MODULE_SCOPE || FLAG_harmony_modules);
-    DCHECK(!IsArrowFunction(kind) || scope_type == ARROW_SCOPE);
     Scope* result = new (zone())
         Scope(zone(), parent, scope_type, ast_value_factory(), kind);
     result->Initialize();
     return result;
   }
 
   Scanner* scanner() const { return scanner_; }
   AstValueFactory* ast_value_factory() const { return ast_value_factory_; }
   int position() { return scanner_->location().beg_pos; }
   int peek_position() { return scanner_->peek_location().beg_pos; }
@@ skipping 2592 matching lines @@
     ArrowFormalParametersUnexpectedToken(&arrow_formals_classifier);
   }
   ExpressionT expression = this->ParseConditionalExpression(
       accept_IN, &arrow_formals_classifier, CHECK_OK);
   if (peek() == Token::ARROW) {
     BindingPatternUnexpectedToken(classifier);
     ValidateArrowFormalParameters(&arrow_formals_classifier, expression,
                                   parenthesized_formals, CHECK_OK);
     Scanner::Location loc(lhs_beg_pos, scanner()->location().end_pos);
     Scope* scope =
-        this->NewScope(scope_, ARROW_SCOPE, FunctionKind::kArrowFunction);
+        this->NewScope(scope_, FUNCTION_SCOPE, FunctionKind::kArrowFunction);
     FormalParametersT parameters(scope);
     if (!arrow_formals_classifier.is_simple_parameter_list()) {
       scope->SetHasNonSimpleParameters();
       parameters.is_simple = false;
     }
 
     Scanner::Location duplicate_loc = Scanner::Location::invalid();
     this->ParseArrowFunctionFormalParameterList(&parameters, expression, loc,
                                                 &duplicate_loc, CHECK_OK);
 
@@ skipping 1245 matching lines @@
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PREPARSER_H