[vala] Support scope = "async" on parameters.

[Luca Bruno <lucabru src gnome org>]

commit 0bd22fbfc6ac8447ef92e877ac8c28eb9e55588b
Author: Luca Bruno <lucabru src gnome org>
Date:   Mon Nov 19 14:06:30 2012 +0100

    Support scope = "async" on parameters.
    
    This flag is still useful on delegates such as ThreadFunc that are
    always scope = "async" by default. The flag on the parameter will
    override the flag has been set on the delegate.

 vala/valaparameter.vala |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/vala/valaparameter.vala b/vala/valaparameter.vala
index b089dde..c42d6f3 100644
--- a/vala/valaparameter.vala
+++ b/vala/valaparameter.vala
@@ -147,6 +147,11 @@ public class Vala.Parameter : Variable {
 				return false;
 			}
 
+			if (has_attribute_argument ("CCode", "scope") && variable_type is DelegateType) {
+				var delegate_type = (DelegateType) variable_type;
+				delegate_type.is_called_once = get_attribute_string ("CCode", "scope") == "async";
+			}
+
 			if (initializer != null) {
 				initializer.target_type = variable_type.copy ();
 				initializer.check (context);