Build errors for i686-apple-darwin

[MarcusCalhoun-Lopez]

I am trying to compile rustix on 32-bit macOS systems.
This means that fix_y2038 is set to true, unlike on 64-bit systems.
The first error is in src/backend/libc/fs/syscalls.rs, where the system attempts a Linux fix.
A possible fix is below.

--- a/src/backend/libc/fs/syscalls.rs
+++ b/src/backend/libc/fs/syscalls.rs
@@ -803,7 +803,7 @@ pub(crate) fn utimensat(
 ) -> io::Result<()> {
     // Old 32-bit version: libc has `utimensat` but it is not y2038 safe by
     // default. But there may be a `__utimensat16` we can use.
-    #[cfg(fix_y2038)]
+    #[cfg(all(fix_y2038, not(apple)))]
     {
         #[cfg(target_env = "gnu")]
         if let Some(libc_utimensat) = __utimensat64.get() {
@@ -1505,7 +1505,7 @@ fn libc_statvfs_to_statvfs(from: c::statvfs) -> StatVfs {
 pub(crate) fn futimens(fd: BorrowedFd<'_>, times: &Timestamps) -> io::Result<()> {
     // Old 32-bit version: libc has `futimens` but it is not y2038 safe by
     // default. But there may be a `__futimens64` we can use.
-    #[cfg(fix_y2038)]
+    #[cfg(all(fix_y2038, not(apple)))]
     {
         #[cfg(target_env = "gnu")]
         if let Some(libc_futimens) = __futimens64.get() {

With that patch, the following four lines of code cause errors because of type incapabilities.
Timespec and c::timespec are not type aliases of one another when fix_y2038 is true.
I am afraid I am not very proficient in Rust yet.
I would be happy to try to put together a pull request with a little guidance.

times.last_access = now;
times.last_modification = now;
return_times[times_index] = times.last_modification;
return_times[times_index] = times.last_access;

[sunfishcode]

This is now released in rustix 0.38.31.