[vala] Fix critical for silent cast

[Luca Bruno <lucabru src gnome org>]

commit fa1aaa932442794fd7e0e5878a7d1e6fa145ccce
Author: Simon Werbeck <simon werbeck gmail com>
Date:   Wed Aug 13 03:08:36 2014 +0200

    Fix critical for silent cast
    
    Fixes bug 696110

 codegen/valaccodebasemodule.vala |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index ca282a1..c96c038 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -5091,6 +5091,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
                        }
                } else {
                        if (expr.is_silent_cast) {
+                               set_cvalue (expr, new CCodeInvalidExpression ());
                                expr.error = true;
                                Report.error (expr.source_reference, "Operation not supported for this type");
                                return;