Adds FreeRTOS stub file

Author: kdschlosser

ext_mod/mpy_freertos/src/mpy_portmacro.c

@@ -250,6 +250,7 @@ static mp_obj_t mp_portDISABLE_INTERRUPTS(void)
 
 MP_DEFINE_CONST_FUN_OBJ_0(mp_portDISABLE_INTERRUPTS_obj, mp_portDISABLE_INTERRUPTS);
 
+
 static mp_obj_t mp_portENABLE_INTERRUPTS(void)
 {
     portENABLE_INTERRUPTS();

ext_mod/mpy_freertos/src/mpy_task.c

@@ -193,9 +193,13 @@ MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_xTaskCreateStatic_obj, 6, 6, mp_xTaskCrea
 
 static mp_obj_t mp_vTaskDelete(mp_obj_t xTaskToDelete_in)
 {
-    mp_obj_freertos_task_t *xTaskToDelete = MP_OBJ_TO_PTR(xTaskToDelete_in);
+    if (xTaskToDelete_in == mp_const_none) {
+        vTaskDelete(NULL);
+    } else {
+        mp_obj_freertos_task_t *xTaskToDelete = MP_OBJ_TO_PTR(xTaskToDelete_in);
+        vTaskDelete(xTaskToDelete->task.handle);
+    }
 
-    vTaskDelete(xTaskToDelete->task.handle);
     return mp_const_none;
 }