linux/amd64 PIE:
	cmd/go:  -62KB (0.5%)
	jujud:  -550KB (0.7%)

For #6853.

Change-Id: Ieb67982abce5832e24b997506f0ae7108f747108
Reviewed-on: https://go-review.googlesource.com/22371
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>