codegen: Fix critial when casting a method prototype access to a delegate
codegen: Fix critial when casting a method prototype access to a delegate

frida/vala,Distrotech/vala,GNOME/vala,jessevdk/vala,spidermonkdust/vala,tjol/vala-tjol,kamanashisroy/aroop,spidermonkdust/vala,spidermonkdust/vala,frida/vala,GNOME/vala,rvu95/vala,rvu95/vala,playya/vala,tjol/vala-tjol,playya/vala,flobrosch/vala-fixes,flobrosch/vala-fixes,rvu95/vala,playya/vala,jessevdk/vala,kamanashisroy/aroop,frida/vala,jessevdk/vala,xdave/pvala,severinh/vala,severinh/vala,frida/vala,kamanashisroy/aroop,flobrosch/vala-fixes,GNOME/vala,Distrotech/vala,Distrotech/vala,frida/vala,GNOME/vala,tjol/vala-tjol,severinh/vala