duplicate generic bits/shm.h for each arch using it, in prep to change

there are more archs sharing the generic 64-bit version of the struct,
which is uniform and much more reasonable, than sharing the current
"generic" one, and depending on how time64 sysvipc is done for 32-bit
archs, even more may be sharing the "64-bit version" in the future.

so, duplicate the current generic to all archs using it (arm, i386,
m68k, microblaze, or1k) so that the generic can be changed freely.

this is recorded as its own commit mainly as a hint to git tooling, to
assist in copy/move tracking.

arch/arm/bits/shm.h

+#define SHMLBA 4096
+
+struct shmid_ds {
+	struct ipc_perm shm_perm;
+	size_t shm_segsz;
+	time_t shm_atime;
+	int __unused1;
+	time_t shm_dtime;
+	int __unused2;
+	time_t shm_ctime;
+	int __unused3;
+	pid_t shm_cpid;
+	pid_t shm_lpid;
+	unsigned long shm_nattch;
+	unsigned long __pad1;
+	unsigned long __pad2;
+};
+
+struct shminfo {
+	unsigned long shmmax, shmmin, shmmni, shmseg, shmall, __unused[4];
+};
+
+struct shm_info {
+	int __used_ids;
+	unsigned long shm_tot, shm_rss, shm_swp;
+	unsigned long __swap_attempts, __swap_successes;
+};
+

arch/i386/bits/shm.h

+#define SHMLBA 4096
+
+struct shmid_ds {
+	struct ipc_perm shm_perm;
+	size_t shm_segsz;
+	time_t shm_atime;
+	int __unused1;
+	time_t shm_dtime;
+	int __unused2;
+	time_t shm_ctime;
+	int __unused3;
+	pid_t shm_cpid;
+	pid_t shm_lpid;
+	unsigned long shm_nattch;
+	unsigned long __pad1;
+	unsigned long __pad2;
+};
+
+struct shminfo {
+	unsigned long shmmax, shmmin, shmmni, shmseg, shmall, __unused[4];
+};
+
+struct shm_info {
+	int __used_ids;
+	unsigned long shm_tot, shm_rss, shm_swp;
+	unsigned long __swap_attempts, __swap_successes;
+};
+

arch/m68k/bits/shm.h

+#define SHMLBA 4096
+
+struct shmid_ds {
+	struct ipc_perm shm_perm;
+	size_t shm_segsz;
+	time_t shm_atime;
+	int __unused1;
+	time_t shm_dtime;
+	int __unused2;
+	time_t shm_ctime;
+	int __unused3;
+	pid_t shm_cpid;
+	pid_t shm_lpid;
+	unsigned long shm_nattch;
+	unsigned long __pad1;
+	unsigned long __pad2;
+};
+
+struct shminfo {
+	unsigned long shmmax, shmmin, shmmni, shmseg, shmall, __unused[4];
+};
+
+struct shm_info {
+	int __used_ids;
+	unsigned long shm_tot, shm_rss, shm_swp;
+	unsigned long __swap_attempts, __swap_successes;
+};
+

arch/microblaze/bits/shm.h

+#define SHMLBA 4096
+
+struct shmid_ds {
+	struct ipc_perm shm_perm;
+	size_t shm_segsz;
+	time_t shm_atime;
+	int __unused1;
+	time_t shm_dtime;
+	int __unused2;
+	time_t shm_ctime;
+	int __unused3;
+	pid_t shm_cpid;
+	pid_t shm_lpid;
+	unsigned long shm_nattch;
+	unsigned long __pad1;
+	unsigned long __pad2;
+};
+
+struct shminfo {
+	unsigned long shmmax, shmmin, shmmni, shmseg, shmall, __unused[4];
+};
+
+struct shm_info {
+	int __used_ids;
+	unsigned long shm_tot, shm_rss, shm_swp;
+	unsigned long __swap_attempts, __swap_successes;
+};
+

arch/or1k/bits/shm.h

+#define SHMLBA 4096
+
+struct shmid_ds {
+	struct ipc_perm shm_perm;
+	size_t shm_segsz;
+	time_t shm_atime;
+	int __unused1;
+	time_t shm_dtime;
+	int __unused2;
+	time_t shm_ctime;
+	int __unused3;
+	pid_t shm_cpid;
+	pid_t shm_lpid;
+	unsigned long shm_nattch;
+	unsigned long __pad1;
+	unsigned long __pad2;
+};
+
+struct shminfo {
+	unsigned long shmmax, shmmin, shmmni, shmseg, shmall, __unused[4];
+};
+
+struct shm_info {
+	int __used_ids;
+	unsigned long shm_tot, shm_rss, shm_swp;
+	unsigned long __swap_attempts, __swap_successes;
+};
+