Scopes: simplfy scope creation for with scopes.

src/ast/scopes.h

Index: src/ast/scopes.h
diff --git a/src/ast/scopes.h b/src/ast/scopes.h
index 1ea06bccc44bc0c9951f07412fa68ec6a4ab5d6b..68929afaa25db1fcc81bbb983ba53c32342ee5c3 100644
--- a/src/ast/scopes.h
+++ b/src/ast/scopes.h
@@ -443,8 +443,7 @@ class Scope: public ZoneObject {
   void set_is_debug_evaluate_scope() { is_debug_evaluate_scope_ = true; }
 
  protected:
-  // Creates a script scope.
-  explicit Scope(Zone* zone);
+  explicit Scope(Zone* zone, ScopeType scope_type = SCRIPT_SCOPE);
 
   void set_language_mode(LanguageMode language_mode) {
     is_strict_ = is_strict(language_mode);