Add gc header size to returned sizeof information

Modules/_testcapimodule.c

 /*
  * C Extension module to test Python interpreter C APIs.
  *
  * The 'test_*' functions exported by this module are run as part of the
  * standard Python regression test, via Lib/test/test_capi.py.
  */
 
 #include "Python.h"
 #include <float.h>
 #include "structmember.h"
@@ skipping 949 matching lines @@
         PyModule_AddObject(m, "ULONG_MAX", PyLong_FromUnsignedLong(ULONG_MAX));
         PyModule_AddObject(m, "FLT_MAX", PyFloat_FromDouble(FLT_MAX));
         PyModule_AddObject(m, "FLT_MIN", PyFloat_FromDouble(FLT_MIN));
         PyModule_AddObject(m, "DBL_MAX", PyFloat_FromDouble(DBL_MAX));
         PyModule_AddObject(m, "DBL_MIN", PyFloat_FromDouble(DBL_MIN));
         PyModule_AddObject(m, "LLONG_MAX", PyLong_FromLongLong(PY_LLONG_MAX));
         PyModule_AddObject(m, "LLONG_MIN", PyLong_FromLongLong(PY_LLONG_MIN));
         PyModule_AddObject(m, "ULLONG_MAX", PyLong_FromUnsignedLongLong(PY_ULLONG_MAX));
         PyModule_AddObject(m, "PY_SSIZE_T_MAX", PyInt_FromSsize_t(PY_SSIZE_T_MAX));
         PyModule_AddObject(m, "PY_SSIZE_T_MIN", PyInt_FromSsize_t(PY_SSIZE_T_MIN));
-        PyModule_AddObject(m, "GC_HEADSIZE", PyInt_FromSsize_t(sizeof(PyGC_Head)));

[Martin v. Löwis, 2008/06/26 18:05:31]

Notice that the constants above are upper-case because they expose the
likewise-spelled C macros, so this doesn't *have* to be upper-case. PEP8 is
silent on this specific issue. 

If this is meant to follow the autoconf convention, it should be
SIZEOF_PYGC_HEAD (i.e. SIZEOF_T).

+        PyModule_AddObject(m, "SIZEOF_PYGC_HEAD", PyInt_FromSsize_t(sizeof(PyGC_Head)));
 
         TestError = PyErr_NewException("_testcapi.error", NULL, NULL);
         Py_INCREF(TestError);
         PyModule_AddObject(m, "error", TestError);
 }