* pthread_cancel.c (pthread_cancel): Use tkill directly. * sysdeps/unix/sysv/linux/pthread_kill.c (__pthread_kill): Disallow sending SIGCANCEL. tst-kill3, tst-kill4, tst-kill5. * tst-kill1.c: New file. * tst-kill2.c: New file. * tst-kill3.c: New file. * tst-kill5.c: New file. * tst-basic7.c: Renamed to... * tst-kill4.c: ...this.