test: put GOROOT/bin before all others in run
test: put GOROOT/bin before all others in run

If you installed a 6g in /usr/bin it interferes
with test/run otherwise.

R=rsc
CC=golang-dev
http://codereview.appspot.com/4944046

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go