Add a separate scope for switch

src/ast-value-factory.h

Index: src/ast-value-factory.h
diff --git a/src/ast-value-factory.h b/src/ast-value-factory.h
index 359cac8133d962b3c9695dca3360c904aae83a5e..efc3b20c25eaf6f7f91567a223e54401246eb2ef 100644
--- a/src/ast-value-factory.h
+++ b/src/ast-value-factory.h
@@ -255,6 +255,7 @@ class AstValue : public ZoneObject {
   F(dot_iterator, ".iterator")                                             \
   F(dot_module, ".module")                                                 \
   F(dot_result, ".result")                                                 \
+  F(dot_switch_tag, ".switch_tag")                                         \
   F(empty, "")                                                             \
   F(eval, "eval")                                                          \
   F(get_template_callsite, "$getTemplateCallSite")                         \