gnu: Update struct shmid_ds for 64-bit time

References:

Common definition for _TIME_BITS=64
https://github.com/bminor/glibc/blob/e78caeb4ff812ae19d24d65f4d4d48508154277b/sysdeps/unix/sysv/linux/bits/types/struct_shmid64_ds_helper.h

Generic implementation used by x86 and arm:
https://github.com/bminor/glibc/blob/e78caeb4ff812ae19d24d65f4d4d48508154277b/sysdeps/unix/sysv/linux/bits/types/struct_shmid_ds.h

PowerPC:
https://github.com/bminor/glibc/blob/e78caeb4ff812ae19d24d65f4d4d48508154277b/sysdeps/unix/sysv/linux/powerpc/bits/types/struct_shmid_ds.h

MIPS: (no changes required)
https://github.com/bminor/glibc/blob/e78caeb4ff812ae19d24d65f4d4d48508154277b/sysdeps/unix/sysv/linux/mips/bits/types/struct_shmid_ds.h

SPARC:
https://github.com/bminor/glibc/blob/e78caeb4ff812ae19d24d65f4d4d48508154277b/sysdeps/unix/sysv/linux/sparc/bits/types/struct_shmid_ds.h

(backport <rust-lang#4433>)
(cherry picked from commit 831b626)

Author: snogge

src/unix/linux_like/linux/gnu/b32/arm/mod.rs

@@ -115,10 +115,13 @@ s! {
         pub shm_perm: crate::ipc_perm,
         pub shm_segsz: size_t,
         pub shm_atime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __unused1: c_ulong,
         pub shm_dtime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __unused2: c_ulong,
         pub shm_ctime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __unused3: c_ulong,
         pub shm_cpid: crate::pid_t,
         pub shm_lpid: crate::pid_t,

src/unix/linux_like/linux/gnu/b32/powerpc.rs

@@ -136,13 +136,20 @@ s! {
 
     pub struct shmid_ds {
         pub shm_perm: crate::ipc_perm,
+        #[cfg(gnu_time_bits64)]
+        pub shm_segsz: size_t,
+        #[cfg(not(gnu_time_bits64))]
         __glibc_reserved1: c_uint,
         pub shm_atime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __glibc_reserved2: c_uint,
         pub shm_dtime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __glibc_reserved3: c_uint,
         pub shm_ctime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __glibc_reserved4: c_uint,
+        #[cfg(not(gnu_time_bits64))]
         pub shm_segsz: size_t,
         pub shm_cpid: crate::pid_t,
         pub shm_lpid: crate::pid_t,

src/unix/linux_like/linux/gnu/b32/sparc/mod.rs

@@ -154,12 +154,18 @@ s! {
 
     pub struct shmid_ds {
         pub shm_perm: crate::ipc_perm,
+        #[cfg(gnu_time_bits64)]
+        pub shm_segsz: size_t,
+        #[cfg(not(gnu_time_bits64))]
         __pad1: c_uint,
         pub shm_atime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __pad2: c_uint,
         pub shm_dtime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __pad3: c_uint,
         pub shm_ctime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         pub shm_segsz: size_t,
         pub shm_cpid: crate::pid_t,
         pub shm_lpid: crate::pid_t,

src/unix/linux_like/linux/gnu/b32/x86/mod.rs

@@ -189,10 +189,13 @@ s! {
         pub shm_perm: crate::ipc_perm,
         pub shm_segsz: size_t,
         pub shm_atime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __unused1: c_ulong,
         pub shm_dtime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __unused2: c_ulong,
         pub shm_ctime: crate::time_t,
+        #[cfg(not(gnu_time_bits64))]
         __unused3: c_ulong,
         pub shm_cpid: crate::pid_t,
         pub shm_lpid: crate::pid_t,