bpo-40137: Add pycore_moduleobject.h internal header (GH-25507)

Add pycore_moduleobject.h internal header file with static inline
functions to access module members:

* _PyModule_GetDict()
* _PyModule_GetDef()
* _PyModule_GetState()

These functions don't check at runtime if their argument has a valid
type and can be inlined even if Python is not built with LTO.

_PyType_GetModuleByDef() uses _PyModule_GetDef().

Replace PyModule_GetState() with _PyModule_GetState() in the
extension modules, considered as performance sensitive:

* _abc
* _functools
* _operator
* _pickle
* _queue
* _random
* _sre
* _struct
* _thread
* _winapi
* array
* posix

The following extensions are now built with the Py_BUILD_CORE_MODULE
macro defined, to be able to use the internal pycore_moduleobject.h
header: _abc, array, _operator, _queue, _sre, _struct.

1 files changed, 2 insertions, 1 deletions

diff --git a/Modules/_struct.c b/Modules/_struct.c
index 1a5e0ae..30ad9f2 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -6,6 +6,7 @@
 #define PY_SSIZE_T_CLEAN
 
 #include "Python.h"
+#include "pycore_moduleobject.h"  // _PyModule_GetState()
 #include "structmember.h"         // PyMemberDef
 #include <ctype.h>
 
@@ -24,7 +25,7 @@ typedef struct {
 static inline _structmodulestate*
 get_struct_state(PyObject *module)
 {
-    void *state = PyModule_GetState(module);
+    void *state = _PyModule_GetState(module);
     assert(state != NULL);
     return (_structmodulestate *)state;
 }