tests: make sure events are from SECCOMP

Makes sure that the PTRACE_EVENT_SECCOMP value is correct and that is
is being passed by the kernel on ptrace events.

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1326905

Signed-off-by: Kees Cook <keescook@chromium.org>
test: run tests in source declaration order

Since the constructor was calling registration, the test list needed to be
explicitly built in reverse.

Signed-off-by: Kees Cook <keescook@chromium.org>
test: convert from ACT_EXT_TSYNC to syscall

Converts tests to use new seccomp syscall instead of prctl.

Signed-off-by: Kees Cook <keescook@chromium.org>