Introduce ModuleScope subclass of DeclarationScope

test/cctest/test-parsing.cc

Index: test/cctest/test-parsing.cc
diff --git a/test/cctest/test-parsing.cc b/test/cctest/test-parsing.cc
index 5f944a88b5cb60df066c2ced1ee4dbd9871b9888..12c6a4012d2e1d5a8422e464af1c56af519e3dea 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -5982,7 +5982,7 @@ TEST(ModuleParsingInternals) {
   CHECK(parser.Parse(&info));
   CHECK(i::Compiler::Analyze(&info));
   i::FunctionLiteral* func = info.literal();
-  i::DeclarationScope* module_scope = func->scope();
+  i::ModuleScope* module_scope = func->scope()->AsModuleScope();
   i::Scope* outer_scope = module_scope->outer_scope();
   CHECK(outer_scope->is_script_scope());
   CHECK_NULL(outer_scope->outer_scope());