Issue #7333: The `posix` module gains an `initgroups()` function providing
access to the initgroups(3) C library call on Unix systems which implement
it.  Patch by Jean-Paul Calderone.
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 7541213..fd58443 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -301,6 +301,9 @@
 /* Define to 1 if you have the `getpeername' function. */
 #undef HAVE_GETPEERNAME
 
+/* Define to 1 if you have the `initgroups' function. */
+#undef HAVE_INITGROUPS
+
 /* Define to 1 if you have the `getpgid' function. */
 #undef HAVE_GETPGID