[vala/0.40] girwriter: Don't write c:include tags for symbols from external packages

[Rico Tzschichholz <ricotz src gnome org>]

commit 38aa11ef10d69418a3a63146cdece034e450c84a
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Apr 29 16:30:43 2019 +0200

    girwriter: Don't write c:include tags for symbols from external packages

 codegen/valagirwriter.vala | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/codegen/valagirwriter.vala b/codegen/valagirwriter.vala
index cc1255375..3dd48211d 100644
--- a/codegen/valagirwriter.vala
+++ b/codegen/valagirwriter.vala
@@ -233,6 +233,9 @@ public class Vala.GIRWriter : CodeVisitor {
                        header_filenames.add (c_header_filename);
                }
                foreach (Symbol symbol in ns.scope.get_symbol_table ().get_values ()) {
+                       if (symbol.external_package) {
+                               continue;
+                       }
                        foreach (unowned string c_header_filename in get_ccode_header_filenames 
(symbol).split (",")) {
                                header_filenames.add (c_header_filename);
                        }