Add a test that a cancellation registered while cancellation is enabled

is not honored while cancellation is disabled.

regress/lib/libpthread/cancel2/Makefile

@@ -0,0 +1,15 @@
+#	$NetBSD: Makefile,v 1.1 2003/07/22 21:26:13 nathanw Exp $
+
+WARNS=1
+
+PROG=   cancel2
+SRCS=   cancel2.c
+
+LDADD=	-lpthread
+
+NOMAN=
+
+regress:
+	./cancel2
+
+.include <bsd.prog.mk>

regress/lib/libpthread/cancel2/cancel2.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+
+int
+main(void)
+{
+	char str1[] = "You should see this.\n";
+	char str2[] = "You shoukd not see this.\n";
+
+	printf("Cancellation test 2: Self-cancellation and disabling.\n");
+
+
+	pthread_cancel(pthread_self());
+
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
+
+	write(STDOUT_FILENO, str1, sizeof(str1));
+
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+
+	write(STDOUT_FILENO, str2, sizeof(str2));
+
+	exit(1);
+}