cmd/cgo: fix build (missing file from earlier CL)
cmd/cgo: fix build (missing file from earlier CL)

TBR=golang-dev
CC=golang-dev
https://codereview.appspot.com/13700045

tv42/old-go,tv42/old-go,tv42/old-go,apparentlymart/golang,tv42/old-go,apparentlymart/golang,tv42/old-go,apparentlymart/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,apparentlymart/golang,apparentlymart/golang,tv42/old-go,apparentlymart/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,apparentlymart/golang