Issue #23685: Fix usage of PyMODINIT_FUNC in _json, _scproxy, nis, pyexpat
_codecs_cn, _codecs_hk, _codecs_iso2022, _codecs_jp, _codecs_kr and _codecs_tw
modules.

pyexpat.c doesn't need to redeclare PyMODINIT_FUNC, it's already declared in
Include/pyport.h.
diff --git a/Modules/_json.c b/Modules/_json.c
index 076859f..3a60243 100644
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -1995,7 +1995,7 @@
         NULL
 };
 
-PyObject*
+PyMODINIT_FUNC
 PyInit__json(void)
 {
     PyObject *m = PyModule_Create(&jsonmodule);
diff --git a/Modules/_scproxy.c b/Modules/_scproxy.c
index 3b2a38e..66b6e34 100644
--- a/Modules/_scproxy.c
+++ b/Modules/_scproxy.c
@@ -249,7 +249,7 @@
 extern "C" {
 #endif
 
-PyObject*
+PyMODINIT_FUNC
 PyInit__scproxy(void)
 {
     return PyModule_Create(&mod_module);
diff --git a/Modules/cjkcodecs/cjkcodecs.h b/Modules/cjkcodecs/cjkcodecs.h
index a45ed12..23642df 100644
--- a/Modules/cjkcodecs/cjkcodecs.h
+++ b/Modules/cjkcodecs/cjkcodecs.h
@@ -401,7 +401,7 @@
         NULL,                                                           \
         NULL                                                            \
     };                                                                  \
-    PyObject*                                                           \
+    PyMODINIT_FUNC                                                      \
     PyInit__codecs_##loc(void)                                          \
     {                                                                   \
         PyObject *m = PyModule_Create(&__module);                       \
diff --git a/Modules/nismodule.c b/Modules/nismodule.c
index 0af495f..64eb5db 100644
--- a/Modules/nismodule.c
+++ b/Modules/nismodule.c
@@ -456,8 +456,8 @@
     NULL
 };
 
-PyObject*
-PyInit_nis (void)
+PyMODINIT_FUNC
+PyInit_nis(void)
 {
     PyObject *m, *d;
     m = PyModule_Create(&nismodule);
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 21cb04a..ce65354 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -1900,16 +1900,6 @@
 #define MODULE_INITFUNC PyInit_pyexpat
 #endif
 
-#ifndef PyMODINIT_FUNC
-#   ifdef MS_WINDOWS
-#       define PyMODINIT_FUNC __declspec(dllexport) void
-#   else
-#       define PyMODINIT_FUNC void
-#   endif
-#endif
-
-PyMODINIT_FUNC MODULE_INITFUNC(void);  /* avoid compiler warnings */
-
 static struct PyModuleDef pyexpatmodule = {
         PyModuleDef_HEAD_INIT,
         MODULE_NAME,