Introduce ModuleScope subclass of DeclarationScope

src/parsing/parser-base.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_PARSER_BASE_H
 #define V8_PARSING_PARSER_BASE_H
 
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
 #include "src/base/hashmap.h"
@@ skipping 600 matching lines @@
   };
 
   DeclarationScope* NewScriptScope() {
     return new (zone()) DeclarationScope(zone(), nullptr, SCRIPT_SCOPE);
   }
 
   DeclarationScope* NewVarblockScope() {
     return new (zone()) DeclarationScope(zone(), scope(), BLOCK_SCOPE);
   }
 
-  DeclarationScope* NewModuleScope(Scope* parent) {
-    DeclarationScope* result =
-        new (zone()) DeclarationScope(zone(), parent, MODULE_SCOPE);
-    // TODO(verwaest): Move into the DeclarationScope constructor.
-    result->DeclareThis(ast_value_factory());
-    return result;
+  ModuleScope* NewModuleScope(DeclarationScope* parent) {
+    return new (zone()) ModuleScope(zone(), parent, ast_value_factory());
   }
 
   DeclarationScope* NewEvalScope(Scope* parent) {
     return new (zone()) DeclarationScope(zone(), parent, EVAL_SCOPE);
   }
 
   Scope* NewScope(ScopeType scope_type) {
     return NewScopeWithParent(scope(), scope_type);
   }
 
@@ skipping 590 matching lines @@
       return this->scanner()->LiteralMatches("constructor", 11);
     }
     bool IsPrototype() {
       return this->scanner()->LiteralMatches("prototype", 9);
     }
 
     bool has_seen_constructor_;
   };
 
   ModuleDescriptor* module() const {
-    return scope()->AsDeclarationScope()->module();
+    return scope()->AsModuleScope()->module();
   }
   Scope* scope() const { return scope_state_->scope(); }
 
   ScopeState* scope_state_;        // Scope stack.
   FunctionState* function_state_;  // Function state stack.
   v8::Extension* extension_;
   FuncNameInferrer* fni_;
   AstValueFactory* ast_value_factory_;  // Not owned.
   typename Traits::Type::Factory ast_node_factory_;
   ParserRecorder* log_;
@@ skipping 2484 matching lines @@
     has_seen_constructor_ = true;
     return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H