runtime: skip TestSignalExitStatus on NetBSD

It doesn't work and I don't know why.

Update #14063.

Change-Id: I42735012cf6247eca5336f29fcf713e08c8477f8
Reviewed-on: https://go-review.googlesource.com/18817
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/runtime/crash_unix_test.go

@@ -136,6 +136,10 @@ func loop(i int, c chan bool) {
 
 func TestSignalExitStatus(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
+	switch runtime.GOOS {
+	case "netbsd":
+		t.Skip("skipping on NetBSD; see https://golang.org/issue/14063")
+	}
 	exe, err := buildTestProg(t, "testprog")
 	if err != nil {
 		t.Fatal(err)