[vala/0.54] vala: Add missing TraverseVisitor.visit_data_type()

[Rico Tzschichholz <ricotz src gnome org>]

commit 5ba49165b7eff4f0484e2d10f9ab5b804c519246
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sun Jan 30 18:07:23 2022 +0100

    vala: Add missing TraverseVisitor.visit_data_type()

 vala/valatraversevisitor.vala | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/vala/valatraversevisitor.vala b/vala/valatraversevisitor.vala
index 34eb7a39a..924ce6963 100644
--- a/vala/valatraversevisitor.vala
+++ b/vala/valatraversevisitor.vala
@@ -150,6 +150,12 @@ public class Vala.TraverseVisitor : CodeVisitor {
                }
        }
 
+       public override void visit_data_type (DataType data_type) {
+               if (func (data_type) == TraverseStatus.CONTINUE) {
+                       data_type.accept_children (this);
+               }
+       }
+
        public override void visit_declaration_statement (DeclarationStatement stmt) {
                if (func (stmt) == TraverseStatus.CONTINUE) {
                        stmt.accept_children (this);