msgctl/msgctl12.c: add new tests

Add new tests for msgctl(2):
IPC_INFO
MSG_INFO
MSG_STAT

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
msgctl/msgctl13.c: add IPC_RMID test

Add IPC_RMID test for msgctl(2)

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>