codegen: Fix critical on unsupported struct field
codegen: Fix critical on unsupported struct field

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