uucore: add WASI support for mode and path_ends_with_terminator

- mode: return default umask (022) on WASI instead of calling libc::umask
- fs: add WASI variant of path_ends_with_terminator using string conversion

src/uucore/src/lib/features/fs.rs

@@ -763,9 +763,12 @@ pub fn are_hardlinks_or_one_way_symlink_to_same_file(source: &Path, target: &Pat
 /// # Arguments
 ///
 /// * `path` - A reference to the path to be checked.
-#[cfg(unix)]
+#[cfg(any(unix, target_os = "wasi"))]
 pub fn path_ends_with_terminator(path: &Path) -> bool {
+    #[cfg(unix)]
     use std::os::unix::prelude::OsStrExt;
+    #[cfg(target_os = "wasi")]
+    use std::os::wasi::ffi::OsStrExt;
     path.as_os_str()
         .as_bytes()
         .last()

src/uucore/src/lib/features/mode.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (vars) fperm srwx
 
-#[cfg(not(unix))]
+#[cfg(windows)]
 use libc::umask;
 
 pub fn parse_numeric(fperm: u32, mut mode: &str, considering_dir: bool) -> Result<u32, String> {
@@ -185,7 +185,7 @@ pub fn get_umask() -> u32 {
         mask.bits() as u32
     }
 
-    #[cfg(not(unix))]
+    #[cfg(windows)]
     {
         // SAFETY: umask always succeeds and doesn't operate on memory. Races are
         // possible but it can't violate Rust's guarantees.
@@ -193,6 +193,12 @@ pub fn get_umask() -> u32 {
         unsafe { umask(mask) };
         mask as u32
     }
+
+    // WASI has no umask; return a typical default (022).
+    #[cfg(not(any(unix, windows)))]
+    {
+        0o022
+    }
 }
 
 #[cfg(test)]