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/include/sys/shm.h b/libc/include/sys/shm.h
new file mode 100644
index 0000000..7836460
--- /dev/null
+++ b/libc/include/sys/shm.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _SYS_SHM_H_
+#define _SYS_SHM_H_
+
+#include <sys/cdefs.h>
+#include <sys/ipc.h>
+#include <sys/types.h>
+
+#include <linux/shm.h>
+
+#define shmid_ds shmid64_ds
+#define SHMLBA 4096
+
+__BEGIN_DECLS
+
+typedef unsigned long shmatt_t;
+
+void* shmat(int, const void*, int) __INTRODUCED_IN_FUTURE;
+int shmctl(int, int, struct shmid_ds*) __INTRODUCED_IN_FUTURE;
+int shmdt(const void*) __INTRODUCED_IN_FUTURE;
+int shmget(key_t, size_t, int) __INTRODUCED_IN_FUTURE;
+
+__END_DECLS
+
+#endif