Fix instance_pos attribute writing in VAPI files
Fix instance_pos attribute writing in VAPI files

Fixes bug 609088.

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