pythongh-85283: Convert grp extension to the limited C API (python#116611)

posixmodule.h: remove check on the limited C API, since these helpers
are not part of the public C API.

Author: vstinner

Include/internal/pycore_global_objects_fini_generated.h

@@ -472,7 +472,6 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(hi)
         STRUCT_FOR_ID(hook)
         STRUCT_FOR_ID(hour)
-        STRUCT_FOR_ID(id)
         STRUCT_FOR_ID(ident)
         STRUCT_FOR_ID(identity_hint)
         STRUCT_FOR_ID(ignore)

Include/internal/pycore_global_strings.h

@@ -1,15 +1,17 @@
-
 /* UNIX group file access module */
 
-// clinic/grpmodule.c.h uses internal pycore_modsupport.h API
-#ifndef Py_BUILD_CORE_BUILTIN
-#  define Py_BUILD_CORE_MODULE 1
+// Need limited C API version 3.13 for PyMem_RawRealloc()
+#include "pyconfig.h"   // Py_GIL_DISABLED
+#ifndef Py_GIL_DISABLED
+#define Py_LIMITED_API 0x030d0000
 #endif
 
 #include "Python.h"
 #include "posixmodule.h"
 
+#include <errno.h>                // ERANGE
 #include <grp.h>                  // getgrgid_r()
+#include <string.h>               // memcpy()
 #include <unistd.h>               // sysconf()
 
 #include "clinic/grpmodule.c.h"
@@ -88,7 +90,7 @@ mkgrent(PyObject *module, struct group *p)
         Py_DECREF(x);
     }
 
-#define SET(i,val) PyStructSequence_SET_ITEM(v, i, val)
+#define SET(i,val) PyStructSequence_SetItem(v, i, val)
     SET(setIndex++, PyUnicode_DecodeFSDefault(p->gr_name));
     if (p->gr_passwd)
             SET(setIndex++, PyUnicode_DecodeFSDefault(p->gr_passwd));

Include/internal/pycore_runtime_init_generated.h

@@ -2,7 +2,6 @@
 
 #ifndef Py_POSIXMODULE_H
 #define Py_POSIXMODULE_H
-#ifndef Py_LIMITED_API
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -34,5 +33,4 @@ extern int _Py_Sigset_Converter(PyObject *, void *);
 #ifdef __cplusplus
 }
 #endif
-#endif   // !Py_LIMITED_API
 #endif   // !Py_POSIXMODULE_H

Include/internal/pycore_unicodeobject_generated.h

@@ -740,3 +740,5 @@ Modules/expat/xmlrole.c	-	error	-
 Modules/_io/_iomodule.c	-	_PyIO_Module	-
 Modules/_sqlite/module.c	-	_sqlite3module	-
 Modules/clinic/md5module.c.h	_md5_md5	_keywords	-
+Modules/clinic/grpmodule.c.h	grp_getgrgid	_keywords	-
+Modules/clinic/grpmodule.c.h	grp_getgrnam	_keywords	-