valac: Add --fast-vapi= commandline argument
valac: Add --fast-vapi= commandline argument

Outputs a file with the given name using CodeWriterType.FAST

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