Add CharacterLiteral.to_string() to fix writing vapi file
Add CharacterLiteral.to_string() to fix writing vapi file

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