SysV SHM: move SHMSEG constants to sys/shm.h

There are planned consumers in linprocfs.

Tested by:	Ricardo Branco <[email protected]>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D45175

Author: kostikbel

sys/kern/sysv_shm.c

@@ -109,10 +109,6 @@ FEATURE(sysv_shm, "System V shared memory segments support");
 
 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
 
-#define	SHMSEG_FREE     	0x0200
-#define	SHMSEG_REMOVED  	0x0400
-#define	SHMSEG_ALLOCATED	0x0800
-
 static int shm_last_free, shm_nused, shmalloced;
 vm_size_t shm_committed;
 static struct shmid_kernel *shmsegs;

sys/sys/shm.h

@@ -152,6 +152,10 @@ struct vmspace;
 
 extern struct shminfo	shminfo;
 
+#define	SHMSEG_FREE     	0x0200
+#define	SHMSEG_REMOVED  	0x0400
+#define	SHMSEG_ALLOCATED	0x0800
+
 void	shmexit(struct vmspace *);
 void	shmfork(struct proc *, struct proc *);