Properly handle set_file_{,handle_}times_now in unix/utimes.rs

This is a POSIX-feature according to
https://pubs.opengroup.org/onlinepubs/9699919799/

By changing mod.rs, I verified that this works on Linux 4.9 and Linux 6.6.

src/unix/utimes.rs

@@ -4,6 +4,7 @@ use std::fs;
 use std::io;
 use std::os::unix::prelude::*;
 use std::path::Path;
+use std::ptr;
 
 #[allow(dead_code)]
 pub fn set_file_times(p: &Path, atime: FileTime, mtime: FileTime) -> io::Result<()> {
@@ -12,8 +13,13 @@ pub fn set_file_times(p: &Path, atime: FileTime, mtime: FileTime) -> io::Result<
 
 #[allow(dead_code)]
 pub fn set_file_times_now(p: &Path) -> io::Result<()> {
-    let time = FileTime::now();
-    set_file_times(p, time, time) // TODO: Do the same trick as on Linux?
+    let p = CString::new(p.as_os_str().as_bytes())?;
+    let rc = unsafe { libc::utimes(p.as_ptr(), ptr::null::<libc::timeval>()) };
+    return if rc == 0 {
+        Ok(())
+    } else {
+        Err(io::Error::last_os_error())
+    };
 }
 
 #[allow(dead_code)]
@@ -66,10 +72,26 @@ pub fn set_file_handle_times(
     };
 }
 
+#[cfg(not(target_env = "uclibc"))]
+#[allow(dead_code)]
+pub fn set_file_handle_times_now(f: &fs::File) -> io::Result<()> {
+    let rc = unsafe { libc::futimes(f.as_raw_fd(), ptr::null::<libc::timeval>()) };
+    return if rc == 0 {
+        Ok(())
+    } else {
+        Err(io::Error::last_os_error())
+    };
+}
+
+#[cfg(target_env = "uclibc")]
 #[allow(dead_code)]
 pub fn set_file_handle_times_now(f: &fs::File) -> io::Result<()> {
-    let time = FileTime::now();
-    set_file_handle_times(f, Some(time), Some(time)) // TODO: Do the same trick as on Linux?
+    let rc = unsafe { libc::futimens(f.as_raw_fd(), ptr::null::<libc::timespec>()) };
+    return if rc == 0 {
+        Ok(())
+    } else {
+        Err(io::Error::last_os_error())
+    };
 }
 
 fn get_times(