cmd/go: cgo for Linux/ARM         Part 4 of CL 5601044 (cgo: Linux/ARM support)
cmd/go: cgo for Linux/ARM
        Part 4 of CL 5601044 (cgo: Linux/ARM support)

R=golang-dev, dave, rsc
CC=golang-dev
http://codereview.appspot.com/5989058
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go