ld: modify macho linkedit segment to enable OS X code signing
ld: modify macho linkedit segment to enable OS X code signing

Move string table to the end of the __LINKEDIT segment.

This change allows Apple's codesign(1) utility to successfully sign
Go binaries, as long as they don't contain DWARF data (-w flag to
8l/6l).  This is because codesign(1) expects the string table to be
the last part of the file.

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/5271050

Committer: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

wesolows/golang,wesolows/golang,wesolows/golang-old,wesolows/golang-old,wesolows/golang-old,wesolows/golang,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang,wesolows/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang-old