pythongh-102304: Fix Py_INCREF() for limited C API 3.9

When Python is built in debug mode (Py_REF_DEBUG macro), Py_INCREF()
and Py_DECREF() of the limited C API 3.9 (and older) now call
Py_IncRef() and Py_DecRef(), since _Py_IncRef() and _Py_DecRef() were
added to Python 3.10.

Author: vstinner

Include/object.h

@@ -612,7 +612,13 @@ static inline Py_ALWAYS_INLINE void Py_INCREF(PyObject *op)
 {
 #if defined(Py_REF_DEBUG) && defined(Py_LIMITED_API)
     // Stable ABI for Python built in debug mode
+#  if Py_LIMITED_API+0 >= 0x030a00A7
     _Py_IncRef(op);
+#  else
+    // _Py_IncRef() was added to Python 3.10.0a7, use Py_IncRef() on older
+    // Python versions. Py_IncRef() accepts NULL whereas _Py_IncRef() doesn't.
+    Py_IncRef(op);
+#  endif
 #else
     // Non-limited C API and limited C API for Python 3.9 and older access
     // directly PyObject.ob_refcnt.
@@ -644,7 +650,13 @@ static inline Py_ALWAYS_INLINE void Py_INCREF(PyObject *op)
 #if defined(Py_REF_DEBUG) && defined(Py_LIMITED_API)
 // Stable ABI for Python built in debug mode
 static inline void Py_DECREF(PyObject *op) {
+#  if Py_LIMITED_API+0 >= 0x030a00A7
     _Py_DecRef(op);
+#  else
+    // _Py_DecRef() was added to Python 3.10.0a7, use Py_DecRef() on older
+    // Python versions. Py_DecRef() accepts NULL whereas _Py_IncRef() doesn't.
+    Py_DecRef(op);
+#  endif
 }
 #define Py_DECREF(op) Py_DECREF(_PyObject_CAST(op))