adds markers to scheduler for identification for plugins

port/threadx_smp/src/tx_thread_schedule.S

@@ -99,6 +99,7 @@ _tx_thread_schedule_thread:
 
     /* }
     while(_tx_thread_execute_ptr == TX_NULL);  */
+scheduler_found_thread:
 
     /* Publish the current thread pointer for this hart, then re-check the
        execute slot to avoid missing a concurrent execute-pointer update.  */
@@ -327,6 +328,7 @@ _tx_thread_synch_return:
 #else
     addi    sp, sp, 16*REGBYTES                         // Recover stack frame
 #endif
+synch_return_exit_label:
     ret                                                 // Return to thread
 
 /* }  */