runtime: wait for main goroutine before setting GOMAXPROCS.
Fixes #3182.
R=golang-dev, dvyukov, rsc
CC=golang-dev, remy
https://golang.org/cl/5732057
diff --git a/src/run.bash b/src/run.bash
index fd3b1f2..fdbf476 100755
--- a/src/run.bash
+++ b/src/run.bash
@@ -26,8 +26,8 @@
time go test std -short -timeout=120s
echo
-echo '# runtime -cpu=1,2,4'
-go test runtime -short -timeout=120s -cpu=1,2,4
+echo '# GOMAXPROCS=2 runtime -cpu=1,2,4'
+GOMAXPROCS=2 go test runtime -short -timeout=120s -cpu=1,2,4
echo
echo '# sync -cpu=10'