fix(kernel): fix kill wait-queue cleanup, RegionId tracking, ReleasePages ownership, and SwitchTo scheduler state

crates/domain/src/scheduler/per_core.rs

@@ -43,6 +43,10 @@ impl PerCoreScheduler {
         self.current = None;
     }
 
+    pub fn set_current(&mut self, thread: ThreadId) {
+        self.current = Some(thread);
+    }
+
     pub fn highest_waiting_priority(&self) -> Option<Priority> {
         self.queue.highest_priority()
     }