tests: add kill.test

* tests/kill.c: New file.
* tests/kill.test: New test.
* tests/.gitignore: Add kill.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add kill.test.
diff --git a/tests/.gitignore b/tests/.gitignore
index 11cc508..8e22944 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -93,6 +93,7 @@
 ipc_msgbuf
 ipc_sem
 ipc_shm
+kill
 ksysent
 ksysent.h
 lchown