posix: Add nl_langinfo
posix: Add nl_langinfo

Fixes 685039.

flobrosch/vala-fixes,rvu95/vala,GNOME/vala,Distrotech/vala,GNOME/vala,GNOME/vala,severinh/vala,frida/vala,spidermonkdust/vala,flobrosch/vala-fixes,playya/vala,GNOME/vala,rvu95/vala,severinh/vala,spidermonkdust/vala,rvu95/vala,Distrotech/vala,frida/vala,playya/vala,severinh/vala,frida/vala,Distrotech/vala,frida/vala,playya/vala,xdave/pvala,frida/vala,flobrosch/vala-fixes,spidermonkdust/vala