Flesh out <sys/msg.h>, <sys/sem.h>, <sys/shm.h>.

Also fix <sys/ipc.h>.

Not useful except to systems/bringup folks for testing. Trivial tests
added, and double-checked under strace to see that things look right.

x86 -- which works differently to everything else -- tested on the host.

Bug: http://b/27952303
Change-Id: I328534e994ae9e90755f545478fba03038c0bb94
diff --git a/tests/Android.bp b/tests/Android.bp
index 8f937a3..0be0f4c 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -107,6 +107,7 @@
         "sstream_test.cpp",
         "sys_epoll_test.cpp",
         "sys_mman_test.cpp",
+        "sys_msg_test.cpp",
         "sys_personality_test.cpp",
         "sys_prctl_test.cpp",
         "sys_procfs_test.cpp",
@@ -114,7 +115,9 @@
         "sys_quota_test.cpp",
         "sys_resource_test.cpp",
         "sys_select_test.cpp",
+        "sys_sem_test.cpp",
         "sys_sendfile_test.cpp",
+        "sys_shm_test.cpp",
         "sys_socket_test.cpp",
         "sys_stat_test.cpp",
         "sys_statvfs_test.cpp",