[hal] Add function for changing HAL Notifier thread priority (#3218)

wpilibj/src/main/java/edu/wpi/first/wpilibj/Notifier.java

@@ -213,4 +213,21 @@ public class Notifier implements AutoCloseable {
       m_processLock.unlock();
     }
   }
+
+  /**
+   * Sets the HAL notifier thread priority.
+   *
+   * <p>The HAL notifier thread is responsible for managing the FPGA's notifier interrupt and waking
+   * up user's Notifiers when it's their time to run. Giving the HAL notifier thread real-time
+   * priority helps ensure the user's real-time Notifiers, if any, are notified to run in a timely
+   * manner.
+   *
+   * @param realTime Set to true to set a real-time priority, false for standard priority.
+   * @param priority Priority to set the thread to. For real-time, this is 1-99 with 99 being
+   *     highest. For non-real-time, this is forced to 0. See "man 7 sched" for more details.
+   * @return True on success.
+   */
+  public static boolean setHALThreadPriority(boolean realTime, int priority) {
+    return NotifierJNI.setHALThreadPriority(realTime, priority);
+  }
 }