The actual cgo is not supported for now. This is just the cgo command.

Change-Id: I25625100ee552971f47e681b7d613cba16a2132f
Reviewed-on: https://go-review.googlesource.com/14446Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>