runtime: temporary disable concurrent GC sweep We see failures on builders, e.g.: http://build.golang.org/log/70bb28cd6bcf8c4f49810a011bb4337a61977bf4
runtime: temporary disable concurrent GC sweep
We see failures on builders, e.g.:
http://build.golang.org/log/70bb28cd6bcf8c4f49810a011bb4337a61977bf4

LGTM=rsc, dave
R=rsc, dave
CC=golang-codereviews
https://codereview.appspot.com/62360043

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