[vala/0.54] vala: Report error on missing gio-2.0 package for async constructors

[Rico Tzschichholz <ricotz src gnome org>]

commit db09aeab8cc4814b9d5797b7d917c96665128386
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Thu Nov 25 20:22:00 2021 +0100

    vala: Report error on missing gio-2.0 package for async constructors
    
    Fixes https://gitlab.gnome.org/GNOME/vala/issues/1256

 vala/valacreationmethod.vala | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/vala/valacreationmethod.vala b/vala/valacreationmethod.vala
index 77b311f31..e59526dd9 100644
--- a/vala/valacreationmethod.vala
+++ b/vala/valacreationmethod.vala
@@ -97,6 +97,12 @@ public class Vala.CreationMethod : Method {
                        this_parameter.check (context);
                }
 
+               if (coroutine && !external_package && !context.has_package ("gio-2.0")) {
+                       error = true;
+                       Report.error (source_reference, "gio-2.0 package required for async constructors");
+                       return false;
+               }
+
                var old_source_file = context.analyzer.current_source_file;
                var old_symbol = context.analyzer.current_symbol;