Rollup merge of rust-lang#140990 - biabbas:vxworks, r=tgross35

VxWorks: updates from recent libc versions

Vxworks changes. Required changes were added to libc in pr rust-lang/libc#4407 and rust-lang/libc#4337

Author: compiler-errors

library/std/src/sys/fs/unix.rs

@@ -1498,11 +1498,10 @@ impl File {
             None => Ok(libc::timespec { tv_sec: 0, tv_nsec: libc::UTIME_OMIT as _ }),
         };
         cfg_if::cfg_if! {
-            if #[cfg(any(target_os = "redox", target_os = "espidf", target_os = "horizon", target_os = "vxworks", target_os = "nuttx"))] {
+            if #[cfg(any(target_os = "redox", target_os = "espidf", target_os = "horizon", target_os = "nuttx"))] {
                 // Redox doesn't appear to support `UTIME_OMIT`.
                 // ESP-IDF and HorizonOS do not support `futimens` at all and the behavior for those OS is therefore
                 // the same as for Redox.
-                // `futimens` and `UTIME_OMIT` are a work in progress for vxworks.
                 let _ = times;
                 Err(io::const_error!(
                     io::ErrorKind::Unsupported,

library/std/src/sys/pal/unix/thread.rs

@@ -222,16 +222,8 @@ impl Thread {
 
     #[cfg(target_os = "vxworks")]
     pub fn set_name(name: &CStr) {
-        // FIXME(libc): adding real STATUS, ERROR type eventually.
-        unsafe extern "C" {
-            fn taskNameSet(task_id: libc::TASK_ID, task_name: *mut libc::c_char) -> libc::c_int;
-        }
-
-        //  VX_TASK_NAME_LEN is 31 in VxWorks 7.
-        const VX_TASK_NAME_LEN: usize = 31;
-
-        let mut name = truncate_cstr::<{ VX_TASK_NAME_LEN }>(name);
-        let res = unsafe { taskNameSet(libc::taskIdSelf(), name.as_mut_ptr()) };
+        let mut name = truncate_cstr::<{ libc::VX_TASK_RENAME_LENGTH - 1 }>(name);
+        let res = unsafe { libc::taskNameSet(libc::taskIdSelf(), name.as_mut_ptr()) };
         debug_assert_eq!(res, libc::OK);
     }