Remove the shim kernel crate

kernel/src/process/credentials/group.rs

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use core::sync::atomic::{AtomicU32, Ordering};
+
+use crate::prelude::*;
+
+#[derive(Debug, Clone, Copy, Pod, Default, PartialEq, Eq, PartialOrd, Ord)]
+#[repr(C)]
+pub struct Gid(u32);
+
+impl Gid {
+    pub const fn new(gid: u32) -> Self {
+        Self(gid)
+    }
+
+    pub const fn new_root() -> Self {
+        Self(ROOT_GID)
+    }
+
+    pub const fn as_u32(&self) -> u32 {
+        self.0
+    }
+
+    pub const fn is_root(&self) -> bool {
+        self.0 == ROOT_GID
+    }
+}
+
+const ROOT_GID: u32 = 0;
+
+#[derive(Debug)]
+pub(super) struct AtomicGid(AtomicU32);
+
+impl AtomicGid {
+    pub const fn new(gid: Gid) -> Self {
+        Self(AtomicU32::new(gid.as_u32()))
+    }
+
+    pub fn set(&self, gid: Gid) {
+        self.0.store(gid.as_u32(), Ordering::Relaxed)
+    }
+
+    pub fn get(&self) -> Gid {
+        Gid(self.0.load(Ordering::Relaxed))
+    }
+}
+
+impl Clone for AtomicGid {
+    fn clone(&self) -> Self {
+        Self(AtomicU32::new(self.0.load(Ordering::Relaxed)))
+    }
+}