patch 8.2.1225: linker errors when building with dynamic Python 3.9

Problem:    Linker errors when building with dynamic Python 3.9.
Solution:   Add #defined items. (closes #6461)

src/if_python3.c

@@ -203,6 +203,9 @@ typedef PySliceObject PySliceObject_T;
 # define PySys_GetObject py3_PySys_GetObject
 # define PySys_SetArgv py3_PySys_SetArgv
 # define PyType_Ready py3_PyType_Ready
+# if PY_VERSION_HEX >= 0x030900b0
+#  define PyType_GetFlags py3_PyType_GetFlags
+# endif
 #undef Py_BuildValue
 # define Py_BuildValue py3_Py_BuildValue
 # define Py_SetPythonHome py3_Py_SetPythonHome
@@ -233,6 +236,9 @@ typedef PySliceObject PySliceObject_T;
 # define PyBytes_FromString py3_PyBytes_FromString
 # undef PyBytes_FromStringAndSize
 # define PyBytes_FromStringAndSize py3_PyBytes_FromStringAndSize
+# if defined(Py_DEBUG) || PY_VERSION_HEX >= 0x030900b0
+#  define _Py_Dealloc py3__Py_Dealloc
+# endif
 # define PyFloat_FromDouble py3_PyFloat_FromDouble
 # define PyFloat_AsDouble py3_PyFloat_AsDouble
 # define PyObject_GenericGetAttr py3_PyObject_GenericGetAttr
@@ -247,7 +253,6 @@ typedef PySliceObject PySliceObject_T;
 # ifdef Py_DEBUG
 #  define _Py_NegativeRefcount py3__Py_NegativeRefcount
 #  define _Py_RefTotal (*py3__Py_RefTotal)
-#  define _Py_Dealloc py3__Py_Dealloc
 #  define PyModule_Create2TraceRefs py3_PyModule_Create2TraceRefs
 # else
 #  define PyModule_Create2 py3_PyModule_Create2
@@ -287,6 +292,10 @@ typedef PySliceObject PySliceObject_T;
 #  define PyObject_NEW(type, typeobj) \
 ( (type *) PyObject_Init( \
 	(PyObject *) _PyObject_DebugMalloc( _PyObject_SIZE(typeobj) ), (typeobj)) )
+# elif PY_VERSION_HEX >= 0x030900b0
+#  undef PyObject_NEW
+#  define PyObject_NEW(type, typeobj) \
+	((type *)py3__PyObject_New(typeobj))
 # endif
 
 /*
@@ -352,6 +361,9 @@ static PyObject* (*py3_PyObject_Repr)(PyObject *);
 static PyObject* (*py3_PyObject_GetItem)(PyObject *, PyObject *);
 static int (*py3_PyObject_IsTrue)(PyObject *);
 static PyObject* (*py3_Py_BuildValue)(char *, ...);
+# if PY_VERSION_HEX >= 0x030900b0
+static int (*py3_PyType_GetFlags)(PyTypeObject *o);
+# endif
 static int (*py3_PyType_Ready)(PyTypeObject *type);
 static int (*py3_PyDict_SetItemString)(PyObject *dp, char *key, PyObject *item);
 static PyObject* (*py3_PyUnicode_FromString)(const char *u);
@@ -396,6 +408,12 @@ static char* (*py3_PyBytes_AsString)(PyObject *bytes);
 static int (*py3_PyBytes_AsStringAndSize)(PyObject *bytes, char **buffer, Py_ssize_t *length);
 static PyObject* (*py3_PyBytes_FromString)(char *str);
 static PyObject* (*py3_PyBytes_FromStringAndSize)(char *str, Py_ssize_t length);
+# if defined(Py_DEBUG) || PY_VERSION_HEX >= 0x030900b0
+static void (*py3__Py_Dealloc)(PyObject *obj);
+# endif
+# if PY_VERSION_HEX >= 0x030900b0
+static PyObject* (*py3__PyObject_New)(PyTypeObject *);
+# endif
 static PyObject* (*py3_PyFloat_FromDouble)(double num);
 static double (*py3_PyFloat_AsDouble)(PyObject *);
 static PyObject* (*py3_PyObject_GenericGetAttr)(PyObject *obj, PyObject *name);
@@ -414,7 +432,6 @@ static void* (*py3_PyCapsule_GetPointer)(PyObject *, char *);
 # ifdef Py_DEBUG
 static void (*py3__Py_NegativeRefcount)(const char *fname, int lineno, PyObject *op);
 static Py_ssize_t* py3__Py_RefTotal;
-static void (*py3__Py_Dealloc)(PyObject *obj);
 static PyObject* (*py3_PyModule_Create2TraceRefs)(struct PyModuleDef* module, int module_api_version);
 # else
 static PyObject* (*py3_PyModule_Create2)(struct PyModuleDef* module, int module_api_version);
@@ -525,6 +542,9 @@ static struct
     {"PyObject_IsTrue", (PYTHON_PROC*)&py3_PyObject_IsTrue},
     {"PyLong_FromLong", (PYTHON_PROC*)&py3_PyLong_FromLong},
     {"PyDict_New", (PYTHON_PROC*)&py3_PyDict_New},
+# if PY_VERSION_HEX >= 0x030900b0
+    {"PyType_GetFlags", (PYTHON_PROC*)&py3_PyType_GetFlags},
+# endif
     {"PyType_Ready", (PYTHON_PROC*)&py3_PyType_Ready},
     {"PyDict_SetItemString", (PYTHON_PROC*)&py3_PyDict_SetItemString},
     {"PyLong_AsLong", (PYTHON_PROC*)&py3_PyLong_AsLong},
@@ -562,6 +582,12 @@ static struct
     {"PyBytes_AsStringAndSize", (PYTHON_PROC*)&py3_PyBytes_AsStringAndSize},
     {"PyBytes_FromString", (PYTHON_PROC*)&py3_PyBytes_FromString},
     {"PyBytes_FromStringAndSize", (PYTHON_PROC*)&py3_PyBytes_FromStringAndSize},
+# if defined(Py_DEBUG) || PY_VERSION_HEX >= 0x030900b0
+    {"_Py_Dealloc", (PYTHON_PROC*)&py3__Py_Dealloc},
+# endif
+# if PY_VERSION_HEX >= 0x030900b0
+    {"_PyObject_New", (PYTHON_PROC*)&py3__PyObject_New},
+# endif
     {"PyFloat_FromDouble", (PYTHON_PROC*)&py3_PyFloat_FromDouble},
     {"PyFloat_AsDouble", (PYTHON_PROC*)&py3_PyFloat_AsDouble},
     {"PyObject_GenericGetAttr", (PYTHON_PROC*)&py3_PyObject_GenericGetAttr},
@@ -578,7 +604,6 @@ static struct
 # ifdef Py_DEBUG
     {"_Py_NegativeRefcount", (PYTHON_PROC*)&py3__Py_NegativeRefcount},
     {"_Py_RefTotal", (PYTHON_PROC*)&py3__Py_RefTotal},
-    {"_Py_Dealloc", (PYTHON_PROC*)&py3__Py_Dealloc},
     {"PyModule_Create2TraceRefs", (PYTHON_PROC*)&py3_PyModule_Create2TraceRefs},
 # else
     {"PyModule_Create2", (PYTHON_PROC*)&py3_PyModule_Create2},
@@ -634,6 +659,15 @@ py3__Py_XDECREF(PyObject *op)
 #  define Py_XDECREF(op) py3__Py_XDECREF(_PyObject_CAST(op))
 # endif
 
+# if PY_VERSION_HEX >= 0x030900b0
+    static inline int
+py3_PyType_HasFeature(PyTypeObject *type, unsigned long feature)
+{
+    return ((PyType_GetFlags(type) & feature) != 0);
+}
+#  define PyType_HasFeature(t,f) py3_PyType_HasFeature(t,f)
+# endif
+
 /*
  * Load library and get all pointers.
  * Parameter 'libname' provides name of DLL.

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1225,
 /**/
     1224,
 /**/