Introduce NewScriptScope that creates a top-level scope

src/parsing/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_PARSING_PREPARSER_H
 #define V8_PARSING_PREPARSER_H
 
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
 #include "src/base/hashmap.h"
@@ skipping 1020 matching lines @@
                                     ast_value_factory, log, this),
         use_counts_(nullptr) {}
 
   // Pre-parse the program from the character stream; returns true on
   // success (even if parsing failed, the pre-parse data successfully
   // captured the syntax error), and false if a stack-overflow happened
   // during parsing.
   PreParseResult PreParseProgram(int* materialized_literals = 0,
                                  bool is_module = false) {
     DCHECK_NULL(scope_state_);
-    Scope* scope = NewScope(nullptr, SCRIPT_SCOPE);
+    Scope* scope = NewScriptScope();
 
     // ModuleDeclarationInstantiation for Source Text Module Records creates a
     // new Module Environment Record whose outer lexical environment record is
     // the global scope.
     if (is_module) {
       scope = NewScope(scope, MODULE_SCOPE);
     }
 
     PreParserFactory factory(nullptr);
     FunctionState top_scope(&function_state_, &scope_state_, scope,
@@ skipping 213 matching lines @@
     const PreParserFormalParameters& parameters, FunctionKind kind,
     FunctionLiteral::FunctionType function_type, bool* ok) {
   return pre_parser_->ParseEagerFunctionBody(function_name, pos, parameters,
                                              kind, function_type, ok);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PREPARSER_H