test: enforce 1 proc in the test
otherwise it fails spuriously with "newfunc allocated unexpectedly" message
when run with GOMAXPROCS>1 (other goroutine allocates).

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6347056
diff --git a/test/closure.go b/test/closure.go
index ae38900..c4a3124 100644
--- a/test/closure.go
+++ b/test/closure.go
@@ -81,6 +81,7 @@
 func newfunc() func(int) int { return func(x int) int { return x } }
 
 func main() {
+	runtime.GOMAXPROCS(1)
 	var fail bool
 
 	go f()