codegen: Use builder API for reference transfer expressions
codegen: Use builder API for reference transfer expressions

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