Use cygwin_{shm,ipc}.h instead of /sys/{shm,ipc}.h throughout.

* sys/ipc.h: Remove.
* sys/shm.h: Remove.
* cygwin_ipc.h: New file.
* cygwin_shm.h: New file.

winsup/cygwin/cygwin_ipc.h

@@ -0,0 +1,53 @@
+/* sys/ipc.h
+
+   Copyright 2001 Red Hat Inc. 
+   Written by Robert Collins <rbtcollins@hotmail.com>
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#ifndef _SYS_IPC_H
+#define _SYS_IPC_H
+
+/* sys/types must be included before sys/ipc.h. We aren't meant to automatically 
+ * include it however 
+ */
+
+struct ipc_perm {
+  uid_t  uid;
+  gid_t  gid;
+  uid_t  cuid;
+  gid_t  cgid;
+  mode_t mode;
+}; 
+
+/* the mode flags used with the _get functions use the low order 9 bits for a mode 
+ * request
+ */
+#define IPC_CREAT  0x0200
+#define IPC_EXCL   0x0400
+#define IPC_NOWAIT 0x0800
+
+/* this is a value that will _never_ be a valid key from ftok */
+#define IPC_PRIVATE -2
+
+/* ctl commands 1000-1fff is ipc reserved */
+#define IPC_RMID 0x1003
+#define IPC_SET  0x1002
+#define IPC_STAT 0x1001
+
+key_t ftok(const char *, int);
+
+#endif /* _SYS_IPC_H */
+
+#ifdef __cplusplus
+}
+#endif