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/libc/Android.bp b/libc/Android.bp
index 6ba8ae6..44b76a2 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1315,6 +1315,9 @@
         "bionic/sync_file_range.cpp",
         "bionic/sysinfo.cpp",
         "bionic/syslog.cpp",
+        "bionic/sys_msg.cpp",
+        "bionic/sys_sem.cpp",
+        "bionic/sys_shm.cpp",
         "bionic/sys_siglist.c",
         "bionic/sys_signame.c",
         "bionic/sys_time.cpp",