gofmt -r: match(...) arguments may be nil; add missing guards
gofmt -r: match(...) arguments may be nil; add missing guards

Fixes issue 1446.

R=rsc
CC=golang-dev
http://codereview.appspot.com/3981043
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go