A+C: Michael MacInnis (individual CLA)

Generated by a+c.

R=gobot
CC=golang-codereviews
https://codereview.appspot.com/140570043
syscall: SysProcAttr job control changes

Making the child's process group the foreground process group and
placing the child in a specific process group involves co-ordination
between the parent and child that must be done post-fork but pre-exec.

LGTM=iant
R=golang-codereviews, gobot, iant, mikioh.mikioh
CC=golang-codereviews
https://codereview.appspot.com/131750044

Committer: Ian Lance Taylor <iant@golang.org>