Add dequeue helper for mutex lock

Currently, mo_mutex_lock() will call mutex_block_atomic() to mark the
running task as TASK_BLOCKED so that it won't be selected by the old scheduler.
To support the ready queue consistency that always keeps runnable tasks,
the dequeuing path should be included when mutex_block_atomic() is
called.

This commit adds _sched_blocked_dequeue() helper and will be applied in
mutex_block_atomic() in the following commit.

Author: vicLin8712

include/sys/task.h

@@ -298,6 +298,10 @@ uint64_t mo_uptime(void);
  */
 void _sched_block(queue_t *wait_q);
 
+/* Dequeue path for task with TASK_BLOCKED state. It must be called before task
+ * state set as TASK_BLOCKED. Currently, this API is used in mutex lock case.*/
+void _sched_block_dequeue(tcb_t *blocked_task);
+
 /* Application Entry Point */
 
 /* The main entry point for the user application.

kernel/task.c

@@ -450,6 +450,15 @@ void sched_wakeup_task(tcb_t *task)
         sched_enqueue_task(task);
 }
 
+/* Dequeue blocked task when mutex lock is triggered */
+void _sched_block_dequeue(tcb_t *blocked_task)
+{
+    if (unlikely(!blocked_task || blocked_task->state != TASK_BLOCKED))
+        return;
+
+    sched_dequeue_task(blocked_task);
+}
+
 /* Efficient Round-Robin Task Selection with O(n) Complexity
  *
  * Selects the next ready task using circular traversal of the master task list.