std::unix::fs::link using direct linkat call for Solaris.

Since we support solaris 11 as minimum, we can get rid
of the runtime overhead.

Author: devnexen

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

@@ -1753,8 +1753,8 @@ pub fn link(original: &Path, link: &Path) -> io::Result<()> {
                     // Android has `linkat` on newer versions, but we happen to know `link`
                     // always has the correct behavior, so it's here as well.
                     cvt(unsafe { libc::link(original.as_ptr(), link.as_ptr()) })?;
-                } else if #[cfg(any(target_os = "macos", target_os = "solaris"))] {
-                    // MacOS (<=10.9) and Solaris 10 lack support for linkat while newer
+                } else if #[cfg(any(target_os = "macos"))] {
+                    // MacOS (<=10.9) lacks support for linkat while newer
                     // versions have it. We want to use linkat if it is available, so we use weak!
                     // to check. `linkat` is preferable to `link` because it gives us a flag to
                     // specify how symlinks should be handled. We pass 0 as the flags argument,