disable "tp_reserved" usage in PyPy

Cython/Utility/Coroutine.c

@@ -1185,7 +1185,7 @@ static PyGetSetDef __pyx_Coroutine_getsets[] = {
     {0, 0, 0, 0, 0}
 };
 
-#if PY_MAJOR_VERSION >= 3
+#if CYTHON_COMPILING_IN_CPYTHON && PY_MAJOR_VERSION >= 3
 static __Pyx_PyAsyncMethodsStruct __pyx_Coroutine_as_async = {
     __Pyx_Coroutine_await, /*am_await*/
     0, /*am_aiter*/
@@ -1202,7 +1202,7 @@ static PyTypeObject __pyx_CoroutineType_type = {
     0,                                  /*tp_print*/
     0,                                  /*tp_getattr*/
     0,                                  /*tp_setattr*/
-#if PY_MAJOR_VERSION >= 3
+#if CYTHON_COMPILING_IN_CPYTHON && PY_MAJOR_VERSION >= 3
     &__pyx_Coroutine_as_async,          /*tp_as_async (tp_reserved)*/
 #else
     0,                                  /*tp_reserved*/

Cython/Utility/ModuleSetupCode.c

@@ -189,7 +189,7 @@
 #if PY_VERSION_HEX >= 0x030500B1
 #define __Pyx_PyAsyncMethodsStruct PyAsyncMethods
 #define __Pyx_PyType_AsAsync(obj) (Py_TYPE(obj)->tp_as_async)
-#elif PY_MAJOR_VERSION >= 3
+#elif CYTHON_COMPILING_IN_CPYTHON && PY_MAJOR_VERSION >= 3
 typedef struct {
     unaryfunc am_await;
     unaryfunc am_aiter;