This is a followup to http://golang.org/cl/6280.
clang -pie fails to link misc/cgo/test on freebsd-amd64.

Change-Id: I6f9575d6bb579f4d38d70707fb9c92e303e30e6f
Reviewed-on: https://go-review.googlesource.com/6520
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>