path/filepath/path_test.go: repair and enable TestAbs
path/filepath/path_test.go: repair and enable TestAbs

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/5759051
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go