runtime: increase timeout in TestStackGrowth

It looks like maybe on slower builders 4 seconds is not enough.
Trying to get rid of the flaky failures.

TBR=iant
CC=golang-codereviews
https://golang.org/cl/86870044

diff --git a/src/pkg/runtime/stack_test.go b/src/pkg/runtime/stack_test.go
index 9a697043684a0c99b622954ca78308ec17f2f637..f3fba6a31c29e01002d6f89f05caab3e40ce9595 100644 (file)
--- a/src/pkg/runtime/stack_test.go
+++ b/src/pkg/runtime/stack_test.go
@@ -162,7 +162,7 @@ func TestStackGrowth(t *testing.T) {
                GC()
                select {
                case <-done:
-               case <-time.After(4 * time.Second):
+               case <-time.After(20 * time.Second):
                        t.Fatal("finalizer did not run")
                }
        }()