Separate Scope into DeclarationScope and Scope

src/ast/modules.h

Index: src/ast/modules.h
diff --git a/src/ast/modules.h b/src/ast/modules.h
index c672f2494917b60bbc310638c7786024410642a5..087b57426bcd8cc4031b8063d81534445e47e956 100644
--- a/src/ast/modules.h
+++ b/src/ast/modules.h
@@ -63,10 +63,9 @@ class ModuleDescriptor : public ZoneObject {
     Zone* zone);
 
   // Check if module is well-formed and report error if not.
-  bool Validate(
-      Scope* module_scope, PendingCompilationErrorHandler* error_handler,
-      Zone* zone) const;
-
+  bool Validate(DeclarationScope* module_scope,
+                PendingCompilationErrorHandler* error_handler,
+                Zone* zone) const;
 
  private:
   struct ModuleEntry : public ZoneObject {