[vala/staging] Revert "Add support for async signal handlers"

[Rico Tzschichholz <ricotz src gnome org>]

commit 648acd6257c07629669cdfd393d2c51e78f65044
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Jan 4 22:27:16 2022 +0100

    Revert "Add support for async signal handlers"
    
    This reverts commit bfcbc0b26c94f8c61f91bd41dc23290536cc9dd9.
    
    Fixes https://gitlab.gnome.org/GNOME/vala/issues/1250

 codegen/valaccodedelegatemodule.vala | 5 -----
 vala/valadelegate.vala               | 2 +-
 2 files changed, 1 insertion(+), 6 deletions(-)
---
diff --git a/codegen/valaccodedelegatemodule.vala b/codegen/valaccodedelegatemodule.vala
index 64ad460c3..a78742f12 100644
--- a/codegen/valaccodedelegatemodule.vala
+++ b/codegen/valaccodedelegatemodule.vala
@@ -402,11 +402,6 @@ public class Vala.CCodeDelegateModule : CCodeArrayModule {
                        last_pos = min_pos;
                }
 
-               if (m.coroutine) {
-                       ccall.add_argument (new CCodeConstant ("NULL"));
-                       ccall.add_argument (new CCodeConstant ("NULL"));
-               }
-
                if (m.return_type is VoidType || m.return_type.is_real_non_null_struct_type ()) {
                        ccode.add_expression (ccall);
                        if (!(d.return_type is VoidType || d.return_type.is_real_non_null_struct_type ())) {
diff --git a/vala/valadelegate.vala b/vala/valadelegate.vala
index eeaabcb69..f2c59b516 100644
--- a/vala/valadelegate.vala
+++ b/vala/valadelegate.vala
@@ -139,7 +139,7 @@ public class Vala.Delegate : TypeSymbol, Callable {
         * @return  true if the specified method is compatible to this callback
         */
        public bool matches_method (Method m, DataType dt) {
-               if (m.coroutine && !(parent_symbol is Signal)) {
+               if (m.coroutine) {
                        // async delegates are not yet supported
                        return false;
                }