[gtk] builder-tool: Don't strip the xml declaration

[Matthias Clasen <matthiasc src gnome org>]

commit c30fc92b3e1030394a287d8dec5a8c4ec015ca46
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Mar 28 19:28:05 2019 -0400

    builder-tool: Don't strip the xml declaration
    
    This is useful for interoperability with other tools.

 gtk/tools/gtk-builder-tool-simplify.c | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/gtk/tools/gtk-builder-tool-simplify.c b/gtk/tools/gtk-builder-tool-simplify.c
index 2c7f4e52cf..44f5f59e53 100644
--- a/gtk/tools/gtk-builder-tool-simplify.c
+++ b/gtk/tools/gtk-builder-tool-simplify.c
@@ -1264,9 +1264,16 @@ dump_element (Element *element,
     g_fprintf (output, "/>\n"); 
 }
 
+static void
+write_xml_declaration (FILE *output)
+{
+  g_fprintf (output, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
+}
+
 static void
 dump_tree (MyParserData *data)
 {
+  write_xml_declaration (data->output);
   dump_element (data->root, data->output, 0);
 }