pythongh-129874: avoid mixing pure python and C implementation of asy…

…ncio (python#129875)

Lib/asyncio/tasks.py

@@ -245,23 +245,23 @@ def uncancel(self):
         return self._num_cancels_requested
 
     def __eager_start(self):
-        prev_task = _swap_current_task(self._loop, self)
+        prev_task = _py_swap_current_task(self._loop, self)
         try:
-            _register_eager_task(self)
+            _py_register_eager_task(self)
             try:
                 self._context.run(self.__step_run_and_handle_result, None)
             finally:
-                _unregister_eager_task(self)
+                _py_unregister_eager_task(self)
         finally:
             try:
-                curtask = _swap_current_task(self._loop, prev_task)
+                curtask = _py_swap_current_task(self._loop, prev_task)
                 assert curtask is self
             finally:
                 if self.done():
                     self._coro = None
                     self = None  # Needed to break cycles when an exception occurs.
                 else:
-                    _register_task(self)
+                    _py_register_task(self)
 
     def __step(self, exc=None):
         if self.done():
@@ -273,11 +273,11 @@ def __step(self, exc=None):
             self._must_cancel = False
         self._fut_waiter = None
 
-        _enter_task(self._loop, self)
+        _py_enter_task(self._loop, self)
         try:
             self.__step_run_and_handle_result(exc)
         finally:
-            _leave_task(self._loop, self)
+            _py_leave_task(self._loop, self)
             self = None  # Needed to break cycles when an exception occurs.
 
     def __step_run_and_handle_result(self, exc):