GH-104787: use bitfields in _asyncio (#104788)

Modules/_asynciomodule.c

@@ -119,25 +119,28 @@ typedef enum {
     PyObject *prefix##_result;                                              \
     PyObject *prefix##_source_tb;                                           \
     PyObject *prefix##_cancel_msg;                                          \
-    fut_state prefix##_state;                                               \
-    int prefix##_log_tb;                                                    \
-    int prefix##_blocking;                                                  \
     PyObject *prefix##_weakreflist;                                         \
-    PyObject *prefix##_cancelled_exc;
+    PyObject *prefix##_cancelled_exc;                                       \
+    fut_state prefix##_state;                                               \
+    /* These bitfields need to be at the end of the struct
+       so that these and bitfields from TaskObj are contiguous.
+    */                                                                      \
+    unsigned prefix##_log_tb: 1;                                            \
+    unsigned prefix##_blocking: 1;
 
 typedef struct {
     FutureObj_HEAD(fut)
 } FutureObj;
 
 typedef struct {
     FutureObj_HEAD(task)
+    unsigned task_must_cancel: 1;
+    unsigned task_log_destroy_pending: 1;
+    int task_num_cancels_requested;
     PyObject *task_fut_waiter;
     PyObject *task_coro;
     PyObject *task_name;
     PyObject *task_context;
-    int task_must_cancel;
-    int task_log_destroy_pending;
-    int task_num_cancels_requested;
 } TaskObj;
 
 typedef struct {