test: add bug469, a case where gccgo gaves an incorrect error
test: add bug469, a case where gccgo gaves an incorrect error

R=golang-dev, dsymonds
CC=golang-dev
http://codereview.appspot.com/6856084

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang